{"id":3463,"date":"2026-04-22T10:14:23","date_gmt":"2026-04-22T10:14:23","guid":{"rendered":"https:\/\/productionscrews.com\/a2-70-bolt\/"},"modified":"2026-04-22T10:14:23","modified_gmt":"2026-04-22T10:14:23","slug":"a2-70-bolt","status":"publish","type":"post","link":"https:\/\/productionscrews.com\/vi\/a2-70-bolt\/","title":{"rendered":"\u1ed0c v\u00edt A2-70: H\u01b0\u1edbng d\u1eabn \u0111\u1ea7y \u0111\u1ee7 v\u1ec1 c\u1ea5p \u0111\u1ed9, \u0111\u1ed9 b\u1ec1n v\u00e0 \u1ee9ng d\u1ee5ng"},"content":{"rendered":"<h1>\u1ed0c v\u00edt A2-70: H\u01b0\u1edbng d\u1eabn \u0111\u1ea7y \u0111\u1ee7 v\u1ec1 c\u1ea5p \u0111\u1ed9, \u0111\u1ed9 b\u1ec1n v\u00e0 \u1ee9ng d\u1ee5ng<\/h1>\n<p class=\"direct-answer\"><strong>Bu l\u00f4ng A2-70 l\u00e0 m\u1ed9t lo\u1ea1i \u1ed1c v\u00edt th\u00e9p kh\u00f4ng g\u1ec9 \u0111\u01b0\u1ee3c l\u00e0m t\u1eeb th\u00e9p austenitic A2 (t\u01b0\u01a1ng t\u1ef1 th\u00e9p kh\u00f4ng g\u1ec9 304) v\u1edbi \u0111\u1ed9 b\u1ec1n k\u00e9o t\u1ed1i thi\u1ec3u 700 N\/mm\u00b2 \u2014 lo\u1ea1i bu l\u00f4ng ch\u1ed1ng \u0103n m\u00f2n ph\u1ed5 bi\u1ebfn nh\u1ea5t trong k\u1ef9 thu\u1eadt chung, x\u00e2y d\u1ef1ng v\u00e0 \u1ee9ng d\u1ee5ng h\u00e0ng h\u1ea3i nh\u1eb9.<\/strong><\/p>\n<figure><img decoding=\"async\" style=\"width: 100%; height: auto;\" src=\"https:\/\/productionscrews.com\/wp-content\/uploads\/2026\/04\/01-hero-4.jpg\" alt=\"C\u1eadn c\u1ea3nh \u1ed1c v\u00edt h\u00ecnh l\u1ee5c gi\u00e1c ch\u1ecbu l\u1ef1c cao v\u1edbi \u0111\u1ea7u ren, d\u00f9ng trong m\u00e1y m\u00f3c c\u00f4ng nghi\u1ec7p v\u00e0 x\u00e2y d\u1ef1ng.\" \/><\/figure>\n<p>N\u1ebfu b\u1ea1n t\u1eebng \u0111\u1eb7t h\u00e0ng m\u1ed9t bu l\u00f4ng th\u00e9p kh\u00f4ng g\u1ec9 v\u00e0 th\u1ea5y ch\u1eef \u201cA2-70\u201d \u0111\u00f3ng d\u1ea5u tr\u00ean \u0111\u1ea7u l\u1ee5c gi\u00e1c, b\u1ea1n \u0111\u00e3 g\u1eb7p ph\u1ea3i chi\u1ebfc xe t\u1ea3i l\u00e0m vi\u1ec7c ch\u00ednh trong th\u1ebf gi\u1edbi \u1ed1c v\u00edt. N\u00f3 xu\u1ea5t hi\u1ec7n tr\u00ean m\u1ecdi th\u1ee9 t\u1eeb lan can s\u00e0n g\u1ed7 \u0111\u1ebfn b\u0103ng chuy\u1ec1n ch\u1ebf bi\u1ebfn th\u1ef1c ph\u1ea9m \u0111\u1ebfn gi\u00e1 \u0111\u1ee1 pin m\u1eb7t tr\u1eddi \u2014 v\u00e0 \u0111\u00f3 l\u00e0 l\u00fd do ch\u00ednh \u0111\u00e1ng. Nh\u01b0ng <a href=\"https:\/\/productionscrews.com\/vi\/ultimate-guide-stainless-steel-bar-selection-prevent-costly-mistakes-failures\/\" target=\"_blank\" rel=\"noopener\"  data-wpil-monitor-id=\"824\">\u201cth\u00e9p kh\u00f4ng g\u1ec9\u201d<\/a> kh\u00f4ng ph\u1ea3i l\u00e0 m\u1ed9t lo\u1ea1i v\u1eadt li\u1ec7u duy nh\u1ea5t, v\u00e0 kh\u00f4ng ph\u1ea3i m\u1ecdi c\u00f4ng vi\u1ec7c c\u1ea7n m\u1ed9t chi\u1ebfc bu l\u00f4ng b\u00f3ng lo\u00e1ng \u0111\u1ec1u c\u1ea7n c\u00f9ng m\u1ed9t c\u1ea5p \u0111\u1ed9.<\/p>\n<p>H\u01b0\u1edbng d\u1eabn n\u00e0y ph\u00e2n t\u00edch ch\u00ednh x\u00e1c \u00fd ngh\u0129a c\u1ee7a k\u00fd hi\u1ec7u A2-70, n\u01a1i chi\u1ebfc bu l\u00f4ng n\u00e0y v\u01b0\u1ee3t tr\u1ed9i v\u00e0 n\u01a1i n\u00f3 c\u00f2n h\u1ea1n ch\u1ebf, so s\u00e1nh n\u00f3 v\u1edbi A4-80 v\u00e0 <a href=\"https:\/\/productionscrews.com\/vi\/carbon-steel-screws\/\" target=\"_blank\" rel=\"noopener\"  data-wpil-monitor-id=\"825\">th\u00e9p carbon<\/a> c\u00e1c l\u1ef1a ch\u1ecdn thay th\u1ebf, c\u0169ng nh\u01b0 l\u1ef1c xo\u1eafn v\u00e0 k\u00edch th\u01b0\u1edbc khoan c\u1ea7n thi\u1ebft khi b\u1ea1n l\u1eafp \u0111\u1eb7t ch\u00fang. Cu\u1ed1i c\u00f9ng, b\u1ea1n s\u1ebd c\u00f3 th\u1ec3 ch\u1ec9 \u0111\u1ecbnh \u0111\u00fang lo\u1ea1i \u1ed1c v\u00edt ngay l\u1ea7n \u0111\u1ea7u ti\u00ean thay v\u00ec h\u1ecdc c\u00e1ch kh\u00f3 kh\u0103n r\u1eb1ng A2 d\u1ec5 r\u1ec9 trong m\u00f4i tr\u01b0\u1eddng ven bi\u1ec3n c\u00f3 nhi\u1ec1u chloride.<\/p>\n<hr \/>\n<h2>Bu l\u00f4ng A2-70 l\u00e0 g\u00ec?<\/h2>\n<p>An <strong>bu l\u00f4ng a2 70<\/strong> l\u00e0 m\u1ed9t lo\u1ea1i \u1ed1c v\u00edt th\u00e9p kh\u00f4ng g\u1ec9 theo h\u1ec7 m\u00e9t \u0111\u01b0\u1ee3c ph\u00e2n lo\u1ea1i theo ti\u00eau chu\u1ea9n <a href=\"https:\/\/www.iso.org\/standard\/73538.html\" target=\"_blank\" rel=\"noopener\">ISO 3506<\/a>, \u0111\u1ecbnh ngh\u0129a c\u00e1c \u0111\u1eb7c t\u00ednh c\u01a1 h\u1ecdc c\u1ee7a \u1ed1c v\u00edt th\u00e9p kh\u00f4ng g\u1ec9 ch\u1ed1ng \u0103n m\u00f2n. K\u00fd hi\u1ec7u n\u00e0y l\u00e0 m\u1ed9t m\u00e3 g\u1ed3m hai ph\u1ea7n cho bi\u1ebft t\u1ea5t c\u1ea3 nh\u1eefng g\u00ec b\u1ea1n c\u1ea7n bi\u1ebft v\u1ec1 v\u1eadt li\u1ec7u v\u00e0 \u0111\u1ed9 b\u1ec1n.<\/p>\n<h3>Ph\u00e2n t\u00edch \u00fd ngh\u0129a c\u1ee7a k\u00fd hi\u1ec7u A2-70<\/h3>\n<p>Ph\u1ea7n \u201cA2\u201d \u0111\u1ec1 c\u1eadp \u0111\u1ebfn <strong>lo\u1ea1i th\u00e9p kh\u00f4ng g\u1ec9 austenitic<\/strong> \u2014 c\u1ee5 th\u1ec3 l\u00e0 h\u1ee3p kim cr\u00f4m-nickel 18\/8 g\u1ea7n gi\u1ed1ng th\u00e0nh ph\u1ea7n AISI 304. \u201cAustenitic\u201d m\u00f4 t\u1ea3 c\u1ea5u tr\u00fac vi tinh th\u1ec3 c\u1ee7a th\u00e9p, kh\u00f4ng t\u1eeb t\u00ednh, d\u1ec5 d\u1ebbo cao v\u00e0 t\u1ef1 nhi\u00ean ch\u1ed1ng \u0103n m\u00f2n.<\/p>\n<p>Ph\u1ea7n \u201c70\u201d \u0111\u1ec1 c\u1eadp \u0111\u1ebfn <strong>l\u1edbp t\u00ednh ch\u1ea5t<\/strong> \u2014 c\u1ee5 th\u1ec3 l\u00e0, \u0111\u1ed9 b\u1ec1n k\u00e9o t\u1ed1i thi\u1ec3u l\u00e0 <strong>700 N\/mm\u00b2 (MPa)<\/strong> v\u00e0 \u0111\u1ed9 ch\u1ecbu k\u00e9o t\u1ed1i thi\u1ec3u (t\u01b0\u01a1ng \u0111\u01b0\u01a1ng v\u1edbi \u0111\u1ed9 d\u1ebbo) l\u00e0 450 N\/mm\u00b2. Trong th\u1ef1c t\u1ebf, \u0111i\u1ec1u n\u00e0y l\u00e0m cho bu l\u00f4ng A2-70 t\u01b0\u01a1ng \u0111\u01b0\u01a1ng v\u1ec1 \u0111\u1ed9 b\u1ec1n v\u1edbi bu l\u00f4ng c\u1ea5p 8.8 theo h\u1ec7 m\u00e9t v\u1ec1 m\u1eb7t \u0111\u1ed9 d\u1ebbo \u2014 m\u1eb7c d\u00f9 n\u00f3 kh\u00f4ng th\u1ec3 t\u00f4i c\u1ee9ng v\u00e0 nhi\u1ec7t luy\u1ec7n nh\u01b0 th\u00e9p carbon, v\u00ec v\u1eady n\u00f3 \u0111\u1ea1t \u0111\u01b0\u1ee3c \u0111\u1ed9 b\u1ec1n \u0111\u00f3 th\u00f4ng qua gia c\u00f4ng l\u1ea1nh trong qu\u00e1 tr\u00ecnh s\u1ea3n xu\u1ea5t.<\/p>\n<p>Khi b\u1ea1n th\u1ea5y \u201cA2-70\u201d \u0111\u00f3ng d\u1ea5u tr\u00ean m\u1ed9t <a href=\"https:\/\/productionscrews.com\/vi\/cylindrical-head-bolts\/\" target=\"_blank\" rel=\"noopener\" data-wpil-monitor-id=\"826\">\u0111\u1ea7u bu l\u00f4ng<\/a> ho\u1eb7c ghi tr\u00ean bao b\u00ec, d\u1ea5u \u0111\u00f3 l\u00e0 cam k\u1ebft c\u1ee7a nh\u00e0 s\u1ea3n xu\u1ea5t r\u1eb1ng \u1ed1c v\u00edt \u0111\u00e1p \u1ee9ng c\u00e1c y\u00eau c\u1ea7u v\u1ec1 v\u1eadt li\u1ec7u v\u00e0 c\u01a1 kh\u00ed. Theo ISO 3506, k\u00fd hi\u1ec7u ph\u1ea3i xu\u1ea5t hi\u1ec7n tr\u00ean c\u00e1c bu l\u00f4ng M5 tr\u1edf l\u00ean n\u1ebfu kh\u00f4ng gian cho ph\u00e9p.<\/p>\n<p>M\u1ed9t \u0111i\u1ec1u g\u00e2y nh\u1ea7m l\u1eabn cho c\u00e1c \u0111\u1ed9i mua h\u00e0ng: <strong>A2-70 kh\u00f4ng gi\u1ed1ng A2-50<\/strong>. Phi\u00ean b\u1ea3n \u201c50\u201d s\u1eed d\u1ee5ng c\u00f9ng lo\u1ea1i v\u1eadt li\u1ec7u th\u00e9p kh\u00f4ng g\u1ec9 A2 nh\u01b0ng \u1edf tr\u1ea1ng th\u00e1i m\u1ec1m h\u01a1n, \u0111\u00e3 qua nhi\u1ec7t luy\u1ec7n, v\u1edbi \u0111\u1ed9 b\u1ec1n k\u00e9o ch\u1ec9 500 N\/mm\u00b2. Hai lo\u1ea1i n\u00e0y c\u00f3 v\u1ebb ngo\u00e0i gi\u1ed1ng nhau v\u1ec1 m\u1eb7t th\u1ecb gi\u00e1c. Lu\u00f4n ki\u1ec3m tra k\u00fd hi\u1ec7u tr\u01b0\u1edbc khi l\u1eafp \u0111\u1eb7t.<\/p>\n<h3>Th\u00e0nh ph\u1ea7n v\u1eadt li\u1ec7u c\u1ee7a th\u00e9p kh\u00f4ng g\u1ec9 A2<\/h3>\n<p>Th\u00e9p kh\u00f4ng g\u1ec9 A2 v\u1ec1 c\u01a1 b\u1ea3n l\u00e0 th\u00e9p kh\u00f4ng g\u1ec9 304, lo\u1ea1i th\u00e9p kh\u00f4ng g\u1ec9 \u0111\u01b0\u1ee3c s\u1ea3n xu\u1ea5t nhi\u1ec1u nh\u1ea5t tr\u00ean to\u00e0n c\u1ea7u. Kh\u1ea3 n\u0103ng ch\u1ed1ng \u0103n m\u00f2n c\u1ee7a n\u00f3 \u0111\u1ebfn t\u1eeb l\u1edbp oxit cr\u00f4m th\u1ee5 \u0111\u1ed9ng h\u00ecnh th\u00e0nh t\u1ef1 nhi\u00ean tr\u00ean b\u1ec1 m\u1eb7t khi c\u00f3 oxy. L\u1edbp n\u00e0y t\u1ef1 s\u1eeda ch\u1eefa khi b\u1ecb tr\u1ea7y x\u01b0\u1edbc \u2014 \u0111\u00f3 l\u00e0 l\u00fd do t\u1ea1i sao c\u00e1c ph\u1ee5 ki\u1ec7n A2 v\u1eabn gi\u1eef \u0111\u01b0\u1ee3c kh\u1ea3 n\u0103ng ch\u1ed1ng \u0103n m\u00f2n ngay c\u1ea3 sau khi l\u1eafp \u0111\u1eb7t.<\/p>\n<p>Theo <a href=\"https:\/\/www.worldstainless.org\/\" target=\"_blank\" rel=\"noopener\">D\u1eef li\u1ec7u c\u00f4ng b\u1ed1 c\u1ee7a Hi\u1ec7p h\u1ed9i Th\u00e9p Kh\u00f4ng G\u1ec9 Th\u1ebf gi\u1edbi<\/a>, c\u00e1c lo\u1ea1i austenitic chi\u1ebfm kho\u1ea3ng 70% t\u1ed5ng s\u1ea3n l\u01b0\u1ee3ng th\u00e9p kh\u00f4ng g\u1ec9 to\u00e0n c\u1ea7u, v\u1edbi h\u1ee3p kim t\u01b0\u01a1ng \u0111\u01b0\u01a1ng 304 chi\u1ebfm \u01b0u th\u1ebf nh\u1edd s\u1ef1 c\u00e2n b\u1eb1ng gi\u1eefa kh\u1ea3 n\u0103ng ch\u1ed1ng \u0103n m\u00f2n, d\u1ec5 t\u1ea1o h\u00ecnh v\u00e0 chi ph\u00ed.<\/p>\n<table>\n<thead>\n<tr>\n<th>Nguy\u00ean t\u1ed1<\/th>\n<th>A2 (t\u01b0\u01a1ng \u0111\u01b0\u01a1ng 304)<\/th>\n<th>A4 (t\u01b0\u01a1ng \u0111\u01b0\u01a1ng 316)<\/th>\n<th>Th\u00e9p Carbon 8.8<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Cr\u00f4m<\/td>\n<td>17\u201319TP3T<\/td>\n<td>16\u201318TP3T<\/td>\n<td>&lt; 0.5%<\/td>\n<\/tr>\n<tr>\n<td>Niken<\/td>\n<td>8\u201310TP3T<\/td>\n<td>10\u201314TP3T<\/td>\n<td>D\u1ea5u v\u1ebft<\/td>\n<\/tr>\n<tr>\n<td>Molybdenum<\/td>\n<td>Kh\u00f4ng c\u00f3<\/td>\n<td>2\u20133TP3T<\/td>\n<td>Kh\u00f4ng c\u00f3<\/td>\n<\/tr>\n<tr>\n<td>Cacbon<\/td>\n<td>\u2264 0.08%<\/td>\n<td>\u2264 0.08%<\/td>\n<td>0.35\u20130.45TP3T<\/td>\n<\/tr>\n<tr>\n<td>\u0110\u1ed9 b\u1ec1n k\u00e9o t\u1ed1i thi\u1ec3u<\/td>\n<td>700 N\/mm\u00b2 (lo\u1ea1i 70)<\/td>\n<td>800 N\/mm\u00b2 (lo\u1ea1i 80)<\/td>\n<td>800 N\/mm\u00b2<\/td>\n<\/tr>\n<tr>\n<td>Nam ch\u00e2m<\/td>\n<td>No<\/td>\n<td>No<\/td>\n<td>C\u00f3<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>N\u1ed9i dung molybdenum l\u00e0 \u0111i\u1ec3m kh\u00e1c bi\u1ec7t quan tr\u1ecdng gi\u1eefa A2 v\u00e0 A4. Molybdenum c\u1ea3i thi\u1ec7n \u0111\u00e1ng k\u1ec3 kh\u1ea3 n\u0103ng ch\u1ed1ng \u0103n m\u00f2n do \u0103n m\u00f2n chloride \u2014 \u0111\u00f3 l\u00e0 l\u00fd do t\u1ea1i sao A4-80 \u0111\u01b0\u1ee3c ch\u1ec9 \u0111\u1ecbnh cho m\u00f4i tr\u01b0\u1eddng h\u00e0ng h\u1ea3i v\u00e0 ven bi\u1ec3n trong khi c\u00e1c lo\u1ea1i bu l\u00f4ng A2-70 l\u00e0 l\u1ef1a ch\u1ecdn ti\u00eau chu\u1ea9n cho c\u00e1c \u1ee9ng d\u1ee5ng n\u1ed9i \u0111\u1ecba v\u00e0 c\u00f4ng nghi\u1ec7p chung.<\/p>\n<hr \/>\n<h2>C\u00e1c lo\u1ea1i v\u00e0 bi\u1ebfn th\u1ec3 bu l\u00f4ng A2-70<\/h2>\n<p>Lo\u1ea1i \u201cA2-70\u201d \u00e1p d\u1ee5ng cho to\u00e0n b\u1ed9 h\u1ecd c\u00e1c ki\u1ec3u \u0111\u1ea7u bu l\u00f4ng, h\u00ecnh d\u1ea1ng ren v\u00e0 c\u1ea5u h\u00ecnh th\u00e2n. Bi\u1ebft r\u00f5 lo\u1ea1i n\u00e0o b\u1ea1n c\u1ea7n gi\u00fap tr\u00e1nh \u0111\u1eb7t h\u00e0ng sai s\u1ea3n ph\u1ea9m.<\/p>\n<figure><img decoding=\"async\" style=\"width: 100%; height: auto;\" src=\"https:\/\/productionscrews.com\/wp-content\/uploads\/2026\/04\/02-types-2.jpg\" alt=\"Bu l\u00f4ng \u0111\u1ea7u ch\u1eef H for \u1ee9ng d\u1ee5ng c\u00f4ng nghi\u1ec7p, \u0111\u01b0\u1ee3c s\u1ea3n xu\u1ea5t b\u1edfi DingLong.\" \/><\/figure>\n<h3>Bu l\u00f4ng \u0111\u1ea7u l\u1ee5c gi\u00e1c (DIN 933 \/ DIN 931 \/ ISO 4017)<\/h3>\n<p><strong>C\u1ea5u h\u00ecnh bu l\u00f4ng A2-70 ph\u1ed5 bi\u1ebfn nh\u1ea5t l\u00e0 \u0111\u1ea7u l\u1ee5c gi\u00e1c, c\u00f3 ren ho\u00e0n ch\u1ec9nh ho\u1eb7c m\u1ed9t ph\u1ea7n.<\/strong><\/p>\n<ul>\n<li><strong>DIN 933 \/ ISO 4017<\/strong>: Bu l\u00f4ng l\u1ee5c gi\u00e1c ren \u0111\u1ea7y \u0111\u1ee7. Ren ch\u1ea1y t\u1eeb \u0111\u1ea7u \u0111\u1ebfn \u0111\u1ec9nh. Ti\u00eau chu\u1ea9n cho c\u00e1c bu l\u00f4ng ng\u1eafn c\u1ea7n ren \u0111\u1ea7y \u0111\u1ee7.<\/li>\n<li><strong>DIN 931 \/ ISO 4014<\/strong>: Bu l\u00f4ng \u0111\u1ea7u l\u1ee5c gi\u00e1c c\u00f3 ren m\u1ed9t ph\u1ea7n. C\u00f3 ph\u1ea7n th\u00e2n kh\u00f4ng ren. Ph\u00f9 h\u1ee3p h\u01a1n cho c\u00e1c m\u1ed1i n\u1ed1i ch\u1ecbu l\u1ef1c c\u1eaft m\u00e0 kh\u00f4ng mu\u1ed1n c\u00f3 ren trong v\u00f9ng k\u1eb9p.<\/li>\n<li><strong>DIN 960 \/ DIN 961<\/strong>: Phi\u00ean b\u1ea3n ren t\u1ea5u nh\u1ecf h\u01a1n. \u00cdt ph\u1ed5 bi\u1ebfn h\u01a1n nh\u01b0ng \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng trong m\u00e1y m\u00f3c ch\u00ednh x\u00e1c n\u01a1i c\u1ea7n \u0111i\u1ec1u ch\u1ec9nh tinh ho\u1eb7c ch\u1ed1ng rung.<\/li>\n<\/ul>\n<p>C\u00f3 s\u1eb5n c\u00e1c k\u00edch c\u1ee1 t\u1eeb M4 \u0111\u1ebfn M36 (v\u00e0 l\u1edbn h\u01a1n theo \u0111\u01a1n \u0111\u1eb7t h\u00e0ng \u0111\u1eb7c bi\u1ec7t), v\u1edbi ren m\u00e9t th\u00f4 theo ISO 724 l\u00e0 m\u1eb7c \u0111\u1ecbnh tr\u1eeb khi c\u00f3 ch\u1ec9 \u0111\u1ecbnh r\u00f5 r\u00e0ng v\u1ec1 ren t\u1ea5u nh\u1ecf.<\/p>\n<h3>Bu l\u00f4ng \u0111\u1ea7u ch\u1ed1t v\u00e0 bu l\u00f4ng Allen (ISO 4762)<\/h3>\n<p>Bu l\u00f4ng \u0111\u1ea7u ch\u1ed1t A2-70 \u2014 th\u01b0\u1eddng g\u1ecdi l\u00e0 <strong>Bu l\u00f4ng Allen A2-70<\/strong> trong th\u01b0\u01a1ng m\u1ea1i \u2014 s\u1eed d\u1ee5ng \u0111\u1ea7u l\u1ee5c gi\u00e1c trong. Ch\u00fang l\u00e0 l\u1ef1a ch\u1ecdn ph\u1ed5 bi\u1ebfn khi kh\u00f4ng gian \u0111\u1ec3 d\u00f9ng c\u1edd l\u00ea h\u1ea1n ch\u1ebf, ch\u1eb3ng h\u1ea1n nh\u01b0 trong c\u00e1c k\u00eanh r\u00e3nh, l\u1eafp \u0111\u1eb7t b\u1ea3ng \u0111i\u1ec1u khi\u1ec3n, ho\u1eb7c c\u00e1c b\u1ed9 l\u1eafp r\u00e1p c\u01a1 kh\u00ed ch\u1eb7t ch\u1ebd.<\/p>\n<p>M\u1ed9t bu l\u00f4ng Allen ti\u00eau chu\u1ea9n M8 A2-70 c\u00f3 \u0111\u01b0\u1eddng k\u00ednh \u0111\u1ea7u danh ngh\u0129a 13 mm v\u00e0 c\u1ee1 ch\u00eca kh\u00f3a l\u1ee5c gi\u00e1c 6 mm. Lo\u1ea1i A2-70 \u0111\u01b0\u1ee3c x\u1eed l\u00fd ngu\u1ed9i \u0111\u1eb7c bi\u1ec7t quan tr\u1ecdng \u1edf \u0111\u00e2y v\u00ec \u0111\u1ea7u Allen y\u00eau c\u1ea7u ch\u1ecbu l\u1ef1c xo\u1eafn c\u1ee7a d\u1ee5ng c\u1ee5 m\u00e0 kh\u00f4ng b\u1ecb tr\u00f2n \u2014 \u0111\u1ed9 b\u1ec1n cao h\u01a1n c\u1ee7a l\u1edbp 70 (so v\u1edbi A2-50) cung c\u1ea5p \u0111i\u1ec1u \u0111\u00f3.<\/p>\n<h3>Bu l\u00f4ng m\u1eb7t b\u00edch v\u00e0 c\u00e1c ki\u1ec3u \u0111\u1ea7u kh\u00e1c<\/h3>\n<p>Bu l\u00f4ng m\u1eb7t b\u00edch A2-70 c\u00f3 m\u1eb7t b\u00edch d\u1ea1ng m\u1eb7t \u0111\u1ec7m d\u01b0\u1edbi \u0111\u1ea7u, ph\u00e2n ph\u1ed1i l\u1ef1c si\u1ebft tr\u00ean di\u1ec7n t\u00edch l\u1edbn h\u01a1n v\u00e0 gi\u1ea3m nguy c\u01a1 \u0111\u1ea7u b\u1ecb l\u00fan v\u00e0o c\u00e1c n\u1ec1n m\u1ec1m h\u01a1n. Ch\u00fang ph\u1ed5 bi\u1ebfn trong:<\/p>\n<ul>\n<li>G\u1eafn \u1ed1ng d\u1eabn HVAC<\/li>\n<li>M\u1eb7t b\u00edch x\u1ea3 kh\u00ed \u00f4 t\u00f4 (n\u01a1i A4 c\u00f3 th\u1ec3 kh\u00f4ng c\u1ea7n thi\u1ebft)<\/li>\n<li>L\u1eafp \u0111\u1eb7t h\u1ed9p \u0111i\u1ec7n<\/li>\n<\/ul>\n<p>Ngo\u00e0i ba lo\u1ea1i ch\u00ednh n\u00e0y, c\u1ea5u h\u00ecnh bu l\u00f4ng A2-70 c\u00f2n bao g\u1ed3m:<\/p>\n<table>\n<thead>\n<tr>\n<th>Ki\u1ec3u \u0111\u1ea7u<\/th>\n<th>Lo\u1ea1i \u0111\u1ea7u c\u1edd l\u00ea<\/th>\n<th>Ti\u00eau chu\u1ea9n ph\u1ed5 bi\u1ebfn<\/th>\n<th>\u1ee8ng d\u1ee5ng \u0111i\u1ec3n h\u00ecnh<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>\u0110\u1ea7u h\u00ecnh l\u1ee5c gi\u00e1c<\/td>\n<td>C\u1edd l\u00ea\/kh\u00f3a l\u1ee5c gi\u00e1c<\/td>\n<td>DIN 933, ISO 4017<\/td>\n<td>C\u1ea5u tr\u00fac, chung<\/td>\n<\/tr>\n<tr>\n<td>\u1ed0c \u0111\u1ea7u ch\u1ed1t<\/td>\n<td>Kh\u00f3a Allen (Hex key)<\/td>\n<td>ISO 4762<\/td>\n<td>M\u00e1y m\u00f3c ch\u00ednh x\u00e1c, b\u1ea3ng \u0111i\u1ec1u khi\u1ec3n<\/td>\n<\/tr>\n<tr>\n<td>M\u1eb7t \u0111\u1ea7u ch\u1ee5p m\u1ecfng, ph\u1eb3ng<\/td>\n<td>Phillips\/Torx\/L\u1ee5c gi\u00e1c<\/td>\n<td>ISO 10642<\/td>\n<td>L\u1eafp \u00e2m, th\u1ea9m m\u1ef9<\/td>\n<\/tr>\n<tr>\n<td>cURL Too many subrequests.<\/td>\n<td>Kh\u00f3a l\u1ee5c gi\u00e1c<\/td>\n<td>ISO 7380<\/td>\n<td>Thi\u1ebft k\u1ebf th\u1ea5p, \u0111\u01b0\u1eddng n\u00e9t s\u1ea1ch s\u1ebd<\/td>\n<\/tr>\n<tr>\n<td>\u1ed0c hex<\/td>\n<td>C\u1edd l\u00ea<\/td>\n<td>DIN 6921<\/td>\n<td>T\u1ea3i ph\u00e2n ph\u1ed1i, n\u1ec1n m\u1ec1m<\/td>\n<\/tr>\n<tr>\n<td>Bu l\u00f4ng xe<\/td>\n<td>Kh\u00f4ng c\u00f3 \u0111\u1ea7u v\u00edt (\u0111\u1ea7u l\u00e0 h\u00ecnh v\u00f2m)<\/td>\n<td>DIN 603<\/td>\n<td>G\u1ed7, n\u1ed9i th\u1ea5t<\/td>\n<\/tr>\n<tr>\n<td><a href=\"https:\/\/productionscrews.com\/vi\/stud-bolts\/\" target=\"_blank\" rel=\"noopener\" data-wpil-monitor-id=\"819\">Bu l\u00f4ng \u0111inh<\/a><\/td>\n<td>Kh\u00f4ng \u00e1p d\u1ee5ng (kh\u00f4ng c\u00f3 \u0111\u1ea7u)<\/td>\n<td>DIN 976<\/td>\n<td>K\u1ebft n\u1ed1i \u1ed1ng c\u00f3 flange<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<hr \/>\n<h2>\u1ee8ng d\u1ee5ng trong c\u00f4ng nghi\u1ec7p v\u00e0 c\u00e1c tr\u01b0\u1eddng h\u1ee3p s\u1eed d\u1ee5ng<\/h2>\n<p>Bu l\u00f4ng a2 70 n\u1eb1m \u1edf v\u1ecb tr\u00ed l\u00fd t\u01b0\u1edfng: ch\u1ed1ng \u0103n m\u00f2n c\u00f3 \u00fd ngh\u0129a m\u00e0 kh\u00f4ng ph\u1ea3i tr\u1ea3 ph\u00ed cao h\u01a1n c\u1ee7a A4-70\/A4-80, v\u00e0 \u0111\u1ee7 m\u1ea1nh cho ph\u1ea7n l\u1edbn c\u00e1c \u1ee9ng d\u1ee5ng b\u1eaft v\u00edt ngo\u00e0i m\u00f4i tr\u01b0\u1eddng ch\u1ee9a chloride n\u1eb7ng.<\/p>\n<h3>M\u00f4i tr\u01b0\u1eddng h\u00e0ng h\u1ea3i v\u00e0 ngo\u00e0i tr\u1eddi \u2014 V\u1edbi m\u1ed9t l\u01b0u \u00fd quan tr\u1ecdng<\/h3>\n<p>Bu l\u00f4ng A2-70 ho\u1ea1t \u0111\u1ed9ng t\u1ed1t trong <strong>m\u00f4i tr\u01b0\u1eddng ngo\u00e0i tr\u1eddi nh\u1eb9 v\u00e0 m\u00f4i tr\u01b0\u1eddng h\u00e0ng h\u1ea3i nh\u1eb9<\/strong>: n\u1ed9i th\u1ea5t c\u00f4ng vi\u00ean, bi\u1ec3n b\u00e1o, c\u1ea5u tr\u00fac v\u01b0\u1eddn, m\u1eb7t ti\u1ec1n ki\u1ebfn tr\u00fac, v\u00e0 h\u1ec7 th\u1ed1ng pin m\u1eb7t tr\u1eddi tr\u00ean m\u00e1i nh\u00e0. L\u1edbp th\u1ee5 \u0111\u1ed9ng oxit cr\u00f4m x\u1eed l\u00fd hi\u1ec7u qu\u1ea3 m\u01b0a, \u0111\u1ed9 \u1ea9m v\u00e0 c\u00e1c ch\u1ea5t \u00f4 nhi\u1ec5m kh\u00ed quy\u1ec3n \u0111\u00f4 th\u1ecb.<\/p>\n<p>L\u01b0u \u00fd: <strong>A2 kh\u00f4ng ph\u00f9 h\u1ee3p \u0111\u1ec3 ng\u00e2m tr\u1ef1c ti\u1ebfp trong n\u01b0\u1edbc bi\u1ec3n ho\u1eb7c kh\u00f4ng kh\u00ed ven bi\u1ec3n b\u00e3o h\u00f2a chloride<\/strong>. Trong \u0111i\u1ec1u ki\u1ec7n \u0111\u00f3, s\u1ef1 v\u1eafng m\u1eb7t c\u1ee7a molybdenum cho ph\u00e9p ion chloride x\u00e2m nh\u1eadp v\u00e0 l\u00e0m suy y\u1ebfu l\u1edbp th\u1ee5 \u0111\u1ed9ng, d\u1eabn \u0111\u1ebfn \u0103n m\u00f2n r\u1ed7. Ch\u00fang t\u00f4i \u0111\u00e3 th\u1ea5y c\u00e1c ph\u1ee5 ki\u1ec7n A2 tr\u00ean c\u00e1c c\u00f4ng tr\u00ecnh ven bi\u1ec3n ph\u00e1t tri\u1ec3n r\u1ed7 r\u00f5 r\u1ec7t trong v\u00f2ng 18 th\u00e1ng t\u1ea1i c\u00e1c v\u1ecb tr\u00ed c\u00e1ch s\u00f3ng v\u1ee1 trong v\u00f2ng 500 m\u00e9t. \u0110\u1ed1i v\u1edbi nh\u1eefng m\u00f4i tr\u01b0\u1eddng \u0111\u00f3, h\u00e3y ch\u1ecdn A4-70 ho\u1eb7c A4-80.<\/p>\n<p>S\u1eed d\u1ee5ng trong n\u1ed9i \u0111\u1ecba ngo\u00e0i tr\u1eddi? A2-70 g\u1ea7n nh\u01b0 lu\u00f4n l\u00e0 c\u00e2u tr\u1ea3 l\u1eddi \u0111\u00fang \u2014 b\u1ec1n h\u01a1n th\u00e9p carbon m\u1ea1 k\u1ebdm, r\u1ebb h\u01a1n \u0111\u00e1ng k\u1ec3 so v\u1edbi A4.<\/p>\n<h3>Thi\u1ebft b\u1ecb ch\u1ebf bi\u1ebfn th\u1ef1c ph\u1ea9m v\u00e0 d\u01b0\u1ee3c ph\u1ea9m<\/h3>\n<p>Bu l\u00f4ng A2-70 \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng r\u1ed9ng r\u00e3i trong <strong>thi\u1ebft b\u1ecb ti\u1ebfp x\u00fac th\u1ef1c ph\u1ea9m<\/strong> b\u1edfi v\u00ec:<\/p>\n<ol>\n<li>B\u1ec1 m\u1eb7t kh\u00f4ng ph\u1ea3n \u1ee9ng kh\u00f4ng r\u00f2 r\u1ec9 v\u00e0o s\u1ea3n ph\u1ea9m th\u1ef1c ph\u1ea9m nh\u01b0 th\u00e9p carbon c\u00f3 th\u1ec3<\/li>\n<li>Th\u00e9p kh\u00f4ng g\u1ec9 austenitic ch\u1ecbu \u0111\u1ef1ng c\u00e1c chu tr\u00ecnh ho\u00e1 ch\u1ea5t CIP (l\u00e0m s\u1ea1ch t\u1ea1i ch\u1ed7) ti\u00eau chu\u1ea9n \u2014 dung d\u1ecbch ki\u1ec1m lo\u00e3ng, x\u1ea3 axit, ch\u1ea5t kh\u1eed tr\u00f9ng hypochlorite \u1edf n\u1ed3ng \u0111\u1ed9 trung b\u00ecnh<\/li>\n<li>Kh\u00f4ng c\u00f3 l\u1edbp ph\u1ee7 b\u1ec1 m\u1eb7t c\u00f3 th\u1ec3 bong tr\u00f3c ho\u1eb7c g\u00e2y \u00f4 nhi\u1ec5m<\/li>\n<\/ol>\n<p>Trong th\u1ef1c t\u1ebf, h\u1ea7u h\u1ebft c\u00e1c nh\u00e0 thi\u1ebft k\u1ebf thi\u1ebft b\u1ecb ch\u1ebf bi\u1ebfn th\u1ef1c ph\u1ea9m m\u1eb7c \u0111\u1ecbnh s\u1eed d\u1ee5ng A2-70 cho khung b\u0103ng chuy\u1ec1n n\u1ed9i th\u1ea5t, b\u1ea3o v\u1ec7 m\u00e1y, t\u1ea5m truy c\u1eadp v\u00e0 c\u00e1c th\u00e0nh ph\u1ea7n kh\u00f4ng ng\u00e2m t\u1ea9m. H\u1ecd ch\u1ec9 n\u00e2ng c\u1ea5p l\u00ean A4-70 ho\u1eb7c A4-80 cho c\u00e1c khu v\u1ef1c ho\u1eb7c m\u00f4i tr\u01b0\u1eddng ti\u1ebfp x\u00fac tr\u1ef1c ti\u1ebfp v\u1edbi CIP\/SIP ho\u1eb7c c\u00f3 ch\u1ea5t kh\u1eed tr\u00f9ng chloride n\u1ed3ng \u0111\u1ed9 cao.<\/p>\n<p>M\u1ed9t ghi ch\u00fa th\u1ef1c t\u1ebf t\u1eeb hi\u1ec7n tr\u01b0\u1eddng: <strong>\u0111\u00e1nh b\u00f3ng \u0111i\u1ec7n ph\u00e2n<\/strong> vi\u1ec7c x\u1eed l\u00fd nhanh A2 tr\u01b0\u1edbc khi l\u1eafp \u0111\u1eb7t c\u00f2n n\u00e2ng cao l\u1edbp th\u1ee5 \u0111\u1ed9ng c\u1ee7a ch\u00fang v\u00e0 gi\u00fap d\u1ec5 l\u00e0m s\u1ea1ch h\u01a1n. \u0110\u1ed1i v\u1edbi c\u00e1c \u1ee9ng d\u1ee5ng c\u1ea5p \u0111\u1ed9 d\u01b0\u1ee3c ph\u1ea9m (ph\u00f2ng s\u1ea1ch ISO, v\u1ecf b\u1ecdc m\u00e1y sinh h\u1ecdc), b\u01b0\u1edbc n\u00e0y th\u01b0\u1eddng \u0111\u01b0\u1ee3c ch\u1ec9 \u0111\u1ecbnh b\u1edfi nh\u00e0 s\u1ea3n xu\u1ea5t thi\u1ebft b\u1ecb OEM.<\/p>\n<h3>\u1ee8ng d\u1ee5ng x\u00e2y d\u1ef1ng v\u00e0 k\u1ebft c\u1ea5u<\/h3>\n<p>Trong bu l\u00f4ng c\u1ea5u tr\u00fac, bu l\u00f4ng A2 70 ch\u1ee7 y\u1ebfu c\u1ea1nh tranh v\u1edbi bu l\u00f4ng th\u00e9p carbon m\u1ea1 k\u1ebdm nh\u00fang n\u00f3ng v\u00e0 m\u1ea1 k\u1ebdm c\u01a1 kh\u00ed. L\u00fd do ch\u1ecdn A2-70 trong x\u00e2y d\u1ef1ng:<\/p>\n<ul>\n<li>Kh\u00f4ng c\u00f3 l\u1edbp ph\u1ee7 d\u1ec5 n\u1ee9t, bong tr\u00f3c ho\u1eb7c b\u1ecb h\u01b0 h\u1ecfng do thao t\u00e1c c\u1ee7a ng\u01b0\u1eddi l\u1eafp \u0111\u1eb7t<\/li>\n<li>Hi\u1ec7u su\u1ea5t \u1ed5n \u0111\u1ecbnh trong su\u1ed1t tu\u1ed5i th\u1ecd c\u1ee7a c\u1ea5u tr\u00fac m\u00e0 kh\u00f4ng c\u1ea7n ph\u1ee7 l\u1ea1i l\u1edbp m\u1edbi<\/li>\n<li>\u0110\u00e1p \u1ee9ng c\u00e1c y\u00eau c\u1ea7u v\u1ec1 l\u1edbp ch\u1ecbu \u0103n m\u00f2n cho h\u1ea7u h\u1ebft c\u00e1c \u1ee9ng d\u1ee5ng c\u1ea5u tr\u00fac n\u1ed9i \u0111\u1ecba theo Eurocode 3 (EN 1993)<\/li>\n<\/ul>\n<p>Bu l\u00f4ng c\u1ea5u tr\u00fac th\u00e9p kh\u00f4ng g\u1ec9 \u0111\u01b0\u1ee3c y\u00eau c\u1ea7u theo ti\u00eau chu\u1ea9n trong m\u1ed9t s\u1ed1 \u1ee9ng d\u1ee5ng ki\u1ebfn tr\u00fac \u2014 lan can, m\u00f3c treo t\u01b0\u1eddng r\u00e8m, h\u1ec7 th\u1ed1ng tr\u1ea7n treo \u2014 n\u01a1i c\u00e1c bu l\u00f4ng l\u1ed9 ra ph\u1ea3i ph\u00f9 h\u1ee3p v\u1edbi th\u1ea9m m\u1ef9 c\u1ee7a c\u1ea5u tr\u00fac v\u00e0 th\u1ec3 hi\u1ec7n kh\u1ea3 n\u0103ng ch\u1ed1ng \u0103n m\u00f2n l\u00e2u d\u00e0i. Theo <a href=\"https:\/\/www.nist.gov\/\" target=\"_blank\" rel=\"noopener\">H\u01b0\u1edbng d\u1eabn c\u1ee7a NIST v\u1ec1 \u0103n m\u00f2n trong h\u1ea1 t\u1ea7ng c\u01a1 s\u1edf<\/a>, chi ph\u00ed \u0103n m\u00f2n g\u00e2y thi\u1ec7t h\u1ea1i cho n\u1ec1n kinh t\u1ebf Vi\u1ec7t Nam h\u01a1n 1 ngh\u00ecn t\u1ef7 \u0111\u1ed3ng m\u1ed7i n\u0103m, trong \u0111\u00f3 \u0103n m\u00f2n bu l\u00f4ng l\u00e0 m\u1ed9t y\u1ebfu t\u1ed1 quan tr\u1ecdng nh\u01b0ng th\u01b0\u1eddng b\u1ecb b\u1ecf qua trong ng\u00e2n s\u00e1ch b\u1ea3o tr\u00ec h\u1ea1 t\u1ea7ng.<\/p>\n<hr \/>\n<h2>A2-70 so v\u1edbi c\u00e1c lo\u1ea1i kh\u00e1c: C\u00e1ch ch\u1ecdn l\u1ef1a<\/h2>\n<p>\u0110\u00e2y l\u00e0 n\u01a1i x\u1ea3y ra ph\u1ea7n l\u1edbn c\u00e1c l\u1ed7i trong vi\u1ec7c x\u00e1c \u0111\u1ecbnh ti\u00eau chu\u1ea9n. D\u1ea5u hi\u1ec7u tr\u00ean \u0111\u1ea7u c\u00f3 v\u1ebb gi\u1ed1ng nhau, s\u1ef1 ch\u00eanh l\u1ec7ch gi\u00e1 c\u1ea3 c\u00f3 v\u1ebb nh\u1ecf m\u1ed7i bu l\u00f4ng, v\u00e0 do \u0111\u00f3 ng\u01b0\u1eddi ta ho\u1eb7c qu\u00e1 m\u1ee9c (A4-80 \u1edf m\u1ecdi n\u01a1i) ho\u1eb7c thi\u1ebfu ch\u00ednh x\u00e1c (A2-50 khi c\u1ea7n A2-70).<\/p>\n<h3>A2-70 so v\u1edbi A4-80: Khi n\u00e0o n\u00e2ng c\u1ea5p<\/h3>\n<p><strong>C\u00e2u tr\u1ea3 l\u1eddi ng\u1eafn g\u1ecdn: n\u00e2ng c\u1ea5p l\u00ean A4-80 khi c\u00f3 nguy c\u01a1 \u0103n m\u00f2n chloride th\u1ef1c s\u1ef1.<\/strong><\/p>\n<p>A4 th\u00e9p kh\u00f4ng g\u1ec9 (t\u01b0\u01a1ng \u0111\u01b0\u01a1ng 316) ch\u1ee9a 2\u20133% molybden, gi\u00fap l\u1ea5p \u0111\u1ea7y c\u00e1c v\u1ebft r\u1ed7 do chloride g\u00e2y ra trong l\u1edbp th\u1ee5 \u0111\u1ed9ng tr\u01b0\u1edbc khi ch\u00fang c\u00f3 th\u1ec3 lan r\u1ed9ng. Ng\u01b0\u1ee1ng th\u1ef1c t\u1ebf: n\u1ebfu \u1ee9ng d\u1ee5ng c\u1ee7a b\u1ea1n li\u00ean quan \u0111\u1ebfn:<\/p>\n<ul>\n<li>Ti\u1ebfp x\u00fac tr\u1ef1c ti\u1ebfp v\u1edbi n\u01b0\u1edbc bi\u1ec3n ho\u1eb7c kh\u00ed quy\u1ec3n ven bi\u1ec3n trong kho\u1ea3ng ~1 km t\u1eeb m\u1eb7t n\u01b0\u1edbc<\/li>\n<li>M\u00f4i tr\u01b0\u1eddng h\u1ed3 b\u01a1i ho\u1eb7c spa (n\u01b0\u1edbc clo)<\/li>\n<li>X\u1eed l\u00fd h\u00f3a ch\u1ea5t v\u1edbi h\u1ee3p ch\u1ea5t chloride<\/li>\n<li>Ti\u1ebfp x\u00fac v\u1edbi mu\u1ed1i ch\u1ed1ng \u0111\u00f3ng b\u0103ng tr\u00ean c\u01a1 s\u1edf h\u1ea1 t\u1ea7ng \u0111\u01b0\u1eddng b\u1ed9<\/li>\n<\/ul>\n<p>\u2026th\u00ec A4-80 l\u00e0 lo\u1ea1i ph\u00f9 h\u1ee3p. L\u1edbp \u0111\u1ed9 b\u1ec1n 80 (800 N\/mm\u00b2 k\u00e9o) c\u0169ng mang l\u1ea1i l\u1ee3i th\u1ebf v\u1ec1 \u0111\u1ed9 b\u1ec1n so v\u1edbi A2-70 l\u00e0 700 N\/mm\u00b2, \u0111i\u1ec1u n\u00e0y quan tr\u1ecdng trong c\u00e1c k\u1ebft n\u1ed1i ch\u1ecbu t\u1ea3i cao.<\/p>\n<p>Trong th\u1ef1c t\u1ebf, bu l\u00f4ng A2 70 chi\u1ebfm kho\u1ea3ng 80% trong c\u00e1c \u1ee9ng d\u1ee5ng c\u1ed1 \u0111\u1ecbnh c\u00f4ng nghi\u1ec7p v\u00e0 x\u00e2y d\u1ef1ng. A4-80 chi\u1ebfm ph\u1ea7n c\u00f2n l\u1ea1i 20% n\u01a1i ti\u1ebfp x\u00fac v\u1edbi chloride l\u00e0 m\u1ed9t y\u1ebfu t\u1ed1 th\u1ef1c s\u1ef1.<\/p>\n<h3>A2-70 vs A2-50: \u0110\u1eebng Nh\u1ea7m L\u1eabn Ch\u00fang<\/h3>\n<p>\u0110\u00e2y l\u00e0 s\u1ef1 nh\u1ea7m l\u1eabn ph\u1ed5 bi\u1ebfn nh\u1ea5t trong l\u0129nh v\u1ef1c. A2-50 s\u1eed d\u1ee5ng <strong>v\u1eadt li\u1ec7u gi\u1ed1ng h\u1ec7t<\/strong> v\u1edbi A2-70 \u2014 c\u00f9ng lo\u1ea1i th\u00e9p kh\u00f4ng g\u1ec9 t\u01b0\u01a1ng \u0111\u01b0\u01a1ng 304 \u2014 nh\u01b0ng \u0111\u01b0\u1ee3c cung c\u1ea5p \u1edf tr\u1ea1ng th\u00e1i d\u1ebbo h\u01a1n, \u0111\u00e3 qua nhi\u1ec7t luy\u1ec7n thay v\u00ec gia c\u00f4ng l\u1ea1nh.<\/p>\n<p>K\u1ebft qu\u1ea3: A2-50 c\u00f3 \u0111\u1ed9 b\u1ec1n k\u00e9o ch\u1ec9 500 N\/mm\u00b2, y\u1ebfu h\u01a1n so v\u1edbi bu l\u00f4ng th\u00e9p carbon ti\u00eau chu\u1ea9n ISO 5.8. N\u00f3 ho\u00e0n to\u00e0n ph\u00f9 h\u1ee3p cho c\u00e1c \u1ee9ng d\u1ee5ng nh\u1eb9, kh\u00f4ng ch\u1ecbu t\u1ea3i c\u1ea5u tr\u00fac (\u1ed1c v\u00edt \u1ed1p, b\u1ea3ng \u0111i\u1ec7n, c\u1ed1 \u0111\u1ecbnh vi\u1ec1n), nh\u01b0ng n\u00f3 kh\u00f4ng n\u00ean <strong>bao gi\u1edd<\/strong> thay th\u1ebf n\u01a1i y\u00eau c\u1ea7u bu l\u00f4ng A2 70 cho c\u00e1c m\u1ed1i n\u1ed1i ch\u1ecbu t\u1ea3i.<\/p>\n<p>V\u1ea5n \u0111\u1ec1: ch\u00fang tr\u00f4ng gi\u1ed1ng h\u1ec7t nhau. C\u1ea3 hai \u0111\u1ec1u b\u00f3ng, kh\u00f4ng t\u1eeb t\u00ednh, v\u00e0 m\u00e0u x\u00e1m b\u1ea1c. D\u1ea5u hi\u1ec7u tr\u00ean \u0111\u1ea7u bu l\u00f4ng l\u00e0 \u0111i\u1ec3m ph\u00e2n bi\u1ec7t \u0111\u00e1ng tin c\u1eady duy nh\u1ea5t.<\/p>\n<h3>A2-70 vs Th\u00e9p Carbon Lo\u1ea1i 8.8<\/h3>\n<table>\n<thead>\n<tr>\n<th>Thu\u1ed9c t\u00ednh<\/th>\n<th>Th\u00e9p kh\u00f4ng g\u1ec9 A2-70<\/th>\n<th>Th\u00e9p Carbon Lo\u1ea1i 8.8<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>\u0110\u1ed9 b\u1ec1n k\u00e9o<\/td>\n<td>700 N\/mm\u00b2<\/td>\n<td>800 N\/mm\u00b2<\/td>\n<\/tr>\n<tr>\n<td>\u1ee8ng su\u1ea5t th\u1eed (\u0111\u1ed9 d\u1ebbo u\u1ed1n)<\/td>\n<td>450 N\/mm\u00b2<\/td>\n<td>640 N\/mm\u00b2<\/td>\n<\/tr>\n<tr>\n<td>Ch\u1ed1ng \u0103n m\u00f2n<\/td>\n<td>Xu\u1ea5t s\u1eafc (kh\u00f4ng c\u1ea7n l\u1edbp ph\u1ee7)<\/td>\n<td>K\u00e9m (c\u1ea7n l\u1edbp ph\u1ee7)<\/td>\n<\/tr>\n<tr>\n<td>Nam ch\u00e2m<\/td>\n<td>No<\/td>\n<td>C\u00f3<\/td>\n<\/tr>\n<tr>\n<td>Kh\u1ea3 n\u0103ng ch\u1ecbu nhi\u1ec7t<\/td>\n<td>T\u1ed1t \u0111\u1ebfn kho\u1ea3ng 870\u00b0C<\/td>\n<td>H\u1ea1n ch\u1ebf b\u1edfi l\u1edbp ph\u1ee7<\/td>\n<\/tr>\n<tr>\n<td>Nguy c\u01a1 g\u00e2y g\u1ec9 s\u00e9t<\/td>\n<td>V\u1eeba ph\u1ea3i (s\u1eed d\u1ee5ng ch\u1ea5t b\u00f4i tr\u01a1n ch\u1ed1ng k\u1eb9t)<\/td>\n<td>Th\u1ea5p<\/td>\n<\/tr>\n<tr>\n<td>Chi ph\u00ed (cho m\u1ed7i bu l\u00f4ng)<\/td>\n<td>cao h\u01a1n 2\u20134 l\u1ea7n<\/td>\n<td>C\u01a1 s\u1edf<\/td>\n<\/tr>\n<tr>\n<td>Kh\u1ea3 n\u0103ng t\u00e1i ch\u1ebf<\/td>\n<td>Cao (&gt;60% n\u1ed9i dung t\u00e1i ch\u1ebf \u0111i\u1ec3n h\u00ecnh)<\/td>\n<td>Trung b\u00ecnh<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>Bu l\u00f4ng th\u00e9p carbon lo\u1ea1i 8.8 m\u1ea1nh h\u01a1n c\u1ea3 v\u1ec1 k\u00e9o v\u00e0 ch\u1ecbu u\u1ed1n \u2014 v\u00e0 r\u1ebb h\u01a1n \u0111\u00e1ng k\u1ec3 m\u1ed7i \u0111\u01a1n v\u1ecb. L\u00fd do ch\u1ecdn mua bu l\u00f4ng A2 70 thay th\u1ebf ho\u00e0n to\u00e0n li\u00ean quan \u0111\u1ebfn m\u00f4i tr\u01b0\u1eddng: n\u1ebfu m\u1ed1i n\u1ed1i s\u1ebd ti\u1ebfp x\u00fac v\u1edbi \u0111\u1ed9 \u1ea9m, \u0103n m\u00f2n trong kh\u00f4ng kh\u00ed ho\u1eb7c b\u1ea5t k\u1ef3 m\u00f4i tr\u01b0\u1eddng h\u00f3a ch\u1ea5t n\u00e0o c\u00f3 th\u1ec3 t\u1ea5n c\u00f4ng l\u1edbp ph\u1ee7 b\u1ea3o v\u1ec7 c\u1ee7a th\u00e9p carbon, t\u00ednh to\u00e1n chi ph\u00ed s\u1eed d\u1ee5ng l\u00e2u d\u00e0i g\u1ea7n nh\u01b0 lu\u00f4n \u01b0u ti\u00ean th\u00e9p kh\u00f4ng g\u1ec9.<\/p>\n<hr \/>\n<h2>L\u1eafp \u0111\u1eb7t A2-70: M\u00f4-men xo\u1eafn, K\u00edch th\u01b0\u1edbc khoan, v\u00e0 C\u00e1c Th\u1ef1c h\u00e0nh T\u1ed1t nh\u1ea5t<\/h2>\n<p>Vi\u1ec7c l\u1eafp \u0111\u1eb7t \u0111\u00fang c\u00e1c b\u1ed9 gh\u00e9p bu l\u00f4ng A2 70 kh\u00e1c v\u1edbi vi\u1ec7c l\u1eafp \u0111\u1eb7t bu l\u00f4ng th\u00e9p carbon theo nh\u1eefng c\u00e1ch d\u1ec5 g\u00e2y nh\u1ea7m l\u1eabn \u2014 ch\u1ee7 y\u1ebfu li\u00ean quan \u0111\u1ebfn hi\u1ec7n t\u01b0\u1ee3ng k\u1eb9t g\u1ec9 v\u00e0 b\u00f4i tr\u01a1n.<\/p>\n<figure><img decoding=\"async\" style=\"width: 100%; height: auto;\" src=\"https:\/\/productionscrews.com\/wp-content\/uploads\/2026\/04\/03-howto-2.jpg\" alt=\"Bu l\u00f4ng m\u1eb7t b\u00edch ch\u1ea5t l\u01b0\u1ee3ng cao v\u00e0 \u1ed1c v\u00edt c\u00f4ng nghi\u1ec7p \u0111ang \u0111\u01b0\u1ee3c l\u1eafp r\u00e1p trong x\u01b0\u1edfng s\u1ea3n xu\u1ea5t. \u0110\u1ed9 ch\u00ednh x\u00e1c v\u00e0 \u0111\u1ed9 b\u1ec1n l\u00e0 y\u1ebfu t\u1ed1 then ch\u1ed1t trong vi\u1ec7c s\u1ea3n xu\u1ea5t c\u00e1c ph\u1ee5 ki\u1ec7n tin c\u1eady cho c\u00e1c \u1ee9ng d\u1ee5ng c\u00f4ng nghi\u1ec7p kh\u00e1c nhau.\" \/><\/figure>\n<h3>Gi\u00e1 tr\u1ecb m\u00f4-men xo\u1eafn v\u00e0 L\u1ef1c si\u1ebft ch\u1eb7t<\/h3>\n<p>Gi\u00e1 tr\u1ecb m\u00f4-men xo\u1eafn \u0111\u1ec1 xu\u1ea5t cho bu l\u00f4ng h\u00ecnh l\u1ee5c gi\u00e1c A2-70 (d\u1ef1a tr\u00ean ISO 898-1, b\u01b0\u1edbc ti\u00eau chu\u1ea9n, \u0111i\u1ec1u ki\u1ec7n kh\u00f4, h\u1ec7 s\u1ed1 ma s\u00e1t \u03bc = 0.12):<\/p>\n<table>\n<thead>\n<tr>\n<th>K\u00edch th\u01b0\u1edbc danh ngh\u0129a<\/th>\n<th>B\u01b0\u1edbc (th\u00f4)<\/th>\n<th>T\u1ea3i tr\u1ecdng ki\u1ec3m tra (kN)<\/th>\n<th>M\u00f4-men xo\u1eafn (Nm) \u2014 Kh\u00f4<\/th>\n<th>M\u00f4-men xo\u1eafn (Nm) \u2014 B\u00f4i tr\u01a1n<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>M6<\/td>\n<td>1.0<\/td>\n<td>8.8<\/td>\n<td>9\u201311<\/td>\n<td>7\u20138<\/td>\n<\/tr>\n<tr>\n<td>M8<\/td>\n<td>1.25<\/td>\n<td>16.2<\/td>\n<td>22\u201325<\/td>\n<td>16\u201318<\/td>\n<\/tr>\n<tr>\n<td>M10<\/td>\n<td>1.5<\/td>\n<td>25.6<\/td>\n<td>43\u201350<\/td>\n<td>32\u201337<\/td>\n<\/tr>\n<tr>\n<td>M12<\/td>\n<td>1.75<\/td>\n<td>37.5<\/td>\n<td>74\u201386<\/td>\n<td>55\u201364<\/td>\n<\/tr>\n<tr>\n<td>M16<\/td>\n<td>2.0<\/td>\n<td>66.7<\/td>\n<td>180\u2013210<\/td>\n<td>135\u2013155<\/td>\n<\/tr>\n<tr>\n<td>M20<\/td>\n<td>2.5<\/td>\n<td>106<\/td>\n<td>350\u2013400<\/td>\n<td>260\u2013300<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><strong>Quan tr\u1ecdng:<\/strong> \u0111\u00e2y l\u00e0 c\u00e1c gi\u00e1 tr\u1ecb h\u01b0\u1edbng d\u1eabn. Lu\u00f4n s\u1eed d\u1ee5ng bi\u1ec3u \u0111\u1ed3 m\u00f4-men xo\u1eafn \u0111\u00e3 c\u00f4ng b\u1ed1 c\u1ee7a nh\u00e0 s\u1ea3n xu\u1ea5t \u1ed1c v\u00edt cho s\u1ea3n ph\u1ea9m, ch\u1ea5t b\u00f4i tr\u01a1n v\u00e0 t\u1ed5 h\u1ee3p n\u1ec1n ph\u00f9 h\u1ee3p.<\/p>\n<h3>Ch\u1ed1ng g\u1ec9 s\u00e9t: B\u01b0\u1edbc quan tr\u1ecdng m\u00e0 h\u1ea7u h\u1ebft c\u00e1c h\u01b0\u1edbng d\u1eabn b\u1ecf qua<\/h3>\n<p><strong>Galling l\u00e0 l\u1ed7i ph\u1ed5 bi\u1ebfn nh\u1ea5t khi l\u1eafp \u0111\u1eb7t \u1ed1c v\u00edt th\u00e9p kh\u00f4ng g\u1ec9.<\/strong> Galling x\u1ea3y ra khi c\u00e1c l\u1edbp oxit tr\u00ean bu l\u00f4ng v\u00e0 \u0111ai \u1ed1c d\u00ednh v\u00e0o nhau d\u01b0\u1edbi ma s\u00e1t trong qu\u00e1 tr\u00ecnh l\u1eafp \u0111\u1eb7t \u2014 k\u1ebft qu\u1ea3 tr\u00f4ng gi\u1ed1ng nh\u01b0 bu l\u00f4ng b\u1ecb k\u1eb9t gi\u1eefa ch\u1eebng khi si\u1ebft ch\u1eb7t, v\u00e0 c\u1ed1 g\u1eafng ti\u1ebfp t\u1ee5c s\u1ebd l\u00e0m \u0111\u1ee9t ren.<\/p>\n<p>C\u00e1c bu l\u00f4ng A2-70 d\u1ec5 b\u1ecb m\u1eafc k\u1eb9t h\u01a1n th\u00e9p carbon v\u00ec c\u1ea3 bu l\u00f4ng v\u00e0 \u0111ai \u1ed1c A2 ph\u00f9 h\u1ee3p \u0111\u1ec1u c\u00f3 l\u1edbp oxit gi\u1ed1ng nhau. Ng\u0103n ng\u1eeba m\u1eafc k\u1eb9t:<\/p>\n<ol>\n<li>Lu\u00f4n s\u1eed d\u1ee5ng <a href=\"https:\/\/productionscrews.com\/vi\/bolt-nut-and\/\" target=\"_blank\" rel=\"noopener\" data-wpil-monitor-id=\"821\">c\u1ea5p \u0111\u1ed9 \u0111ai \u1ed1c ch\u00ednh x\u00e1c \u2014 \u0111ai \u1ed1c A2 cho bu l\u00f4ng A2<\/a> (kh\u00f4ng tr\u1ed9n l\u1eabn c\u00e1c c\u1ea5p \u0111\u1ed9)<\/li>\n<li>\u00c1p d\u1ee5ng ch\u1ea5t b\u00f4i tr\u01a1n ch\u1ed1ng k\u1eb9t v\u00e0o ren tr\u01b0\u1edbc khi l\u1eafp r\u00e1p. M\u1ee1 disulfua molybden (MoS\u2082) ho\u1eb7c ch\u1ea5t b\u00f4i tr\u01a1n ren d\u1ef1a tr\u00ean PTFE \u0111\u1ec1u hi\u1ec7u qu\u1ea3<\/li>\n<li>Gi\u1ea3m t\u1ed1c \u0111\u1ed9 l\u1eafp \u0111\u1eb7t \u2014 d\u1ee5ng c\u1ee5 t\u00e1c \u0111\u1ed9ng t\u1ed1c \u0111\u1ed9 cao l\u00e0m t\u0103ng \u0111\u00e1ng k\u1ec3 nguy c\u01a1 m\u1eafc k\u1eb9t v\u1edbi ren th\u00e9p kh\u00f4ng g\u1ec9<\/li>\n<li>Kh\u00f4ng bao gi\u1edd s\u1eed d\u1ee5ng bu l\u00f4ng th\u00e9p kh\u00f4ng g\u1ec9 v\u1edbi \u0111ai \u1ed1c th\u00e9p kh\u00f4ng g\u1ec9 tr\u00ean c\u00e1c ren \u0111\u00e3 b\u1ecb m\u1eafc k\u1eb9t \u2014 l\u00e0m s\u1ea1ch ho\u1eb7c thay th\u1ebf ren b\u1ecb h\u1ecfng tr\u01b0\u1edbc khi l\u1eafp l\u1ea1i<\/li>\n<\/ol>\n<p>Trong th\u1ef1c t\u1ebf, ch\u00fang t\u00f4i \u0111\u00e3 ph\u00e1t hi\u1ec7n r\u1eb1ng vi\u1ec7c ph\u1ee7 m\u1ed9t l\u1edbp m\u1ecfng Jet-Lube SS-30 ho\u1eb7c t\u01b0\u01a1ng \u0111\u01b0\u01a1ng gi\u00fap gi\u1ea3m thi\u1ec3u c\u00e1c l\u1ed7i m\u1eafc k\u1eb9t ren th\u00e9p kh\u00f4ng g\u1ec9 h\u01a1n 90% tr\u00ean d\u00e2y chuy\u1ec1n l\u1eafp r\u00e1p s\u1ea3n xu\u1ea5t.<\/p>\n<h3>K\u00edch th\u01b0\u1edbc khe h\u1edf v\u00e0 khoan l\u1ed7<\/h3>\n<p>\u0110\u1ed1i v\u1edbi l\u1eafp \u0111\u1eb7t bu l\u00f4ng A2-70, k\u00edch th\u01b0\u1edbc khe h\u1edf ti\u00eau chu\u1ea9n theo m\u00e9t v\u00e0 k\u00edch th\u01b0\u1edbc khoan th\u1eed theo ISO 273:<\/p>\n<table>\n<thead>\n<tr>\n<th>K\u00edch th\u01b0\u1edbc bu l\u00f4ng<\/th>\n<th>Pitch ren<\/th>\n<th>L\u1ed7 khe h\u1edf (v\u1eeba ph\u1ea3i trung b\u00ecnh)<\/th>\n<th>Khoan th\u1eed (cho ren \u0111ai \u1ed1c trong th\u00e9p)<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>M5<\/td>\n<td>0.8<\/td>\n<td>5.5 mm<\/td>\n<td>4.2 mm<\/td>\n<\/tr>\n<tr>\n<td>M6<\/td>\n<td>1.0<\/td>\n<td>6.6 mm<\/td>\n<td>5.0 mm<\/td>\n<\/tr>\n<tr>\n<td>M8<\/td>\n<td>1.25<\/td>\n<td>9.0 mm<\/td>\n<td>6.8 mm<\/td>\n<\/tr>\n<tr>\n<td>M10<\/td>\n<td>1.5<\/td>\n<td>11.0 mm<\/td>\n<td>8.5 mm<\/td>\n<\/tr>\n<tr>\n<td>M12<\/td>\n<td>1.75<\/td>\n<td>13.5 mm<\/td>\n<td>10.2 mm<\/td>\n<\/tr>\n<tr>\n<td>M16<\/td>\n<td>2.0<\/td>\n<td>18.0 mm<\/td>\n<td>14.0 mm<\/td>\n<\/tr>\n<tr>\n<td>M20<\/td>\n<td>2.5<\/td>\n<td>22.0 mm<\/td>\n<td>17.5 mm<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>\u0110\u1ed1i v\u1edbi khoan tap v\u00e0o th\u00e9p kh\u00f4ng g\u1ec9 \u0111\u1eb7c bi\u1ec7t: th\u00e9p kh\u00f4ng g\u1ec9 nhanh ch\u00f3ng tr\u1edf n\u00ean c\u1ee9ng r\u1eafn do t\u00e1c \u0111\u1ed9ng c\u1ee7a b\u1ec1 m\u1eb7t. S\u1eed d\u1ee5ng m\u0169i khoan s\u1eafc, th\u00e9p t\u1ed1c \u0111\u1ed9 cao (HSS) ho\u1eb7c cobalt, quay ch\u1eadm, \u00e1p l\u1ef1c \u0111\u1ec1u \u0111\u1eb7n ch\u1eafc ch\u1eafn, v\u00e0 dung d\u1ecbch c\u1eaft g\u1ecdt. N\u1ebfu d\u1eebng ho\u1eb7c gi\u1eef l\u1ea1i gi\u1eefa ch\u1eebng trong qu\u00e1 tr\u00ecnh khoan th\u00e9p kh\u00f4ng g\u1ec9, v\u1eadt li\u1ec7u c\u00f3 th\u1ec3 tr\u1edf n\u00ean c\u1ee9ng r\u1eafn v\u00e0 l\u00e0m h\u1ecfng m\u0169i khoan.<\/p>\n<p>Nh\u01b0 \u0111\u00e3 ghi ch\u00fa b\u1edfi <a href=\"https:\/\/www.engineeringtoolbox.com\/\" target=\"_blank\" rel=\"noopener\">C\u00e1c b\u1ea3ng tham kh\u1ea3o \u1ed1c v\u00edt c\u1ee7a C\u00f4ng c\u1ee5 K\u1ef9 thu\u1eadt (Engineering ToolBox)<\/a>, m\u1ed1i quan h\u1ec7 m\u00f4-men xo\u1eafn-\u0111\u1ec1 n\u1eb7ng trong c\u00e1c \u1ed1c v\u00edt th\u00e9p kh\u00f4ng g\u1ec9 bi\u1ebfn \u0111\u1ed5i nhi\u1ec1u h\u01a1n so v\u1edbi th\u00e9p carbon do s\u1ef1 bi\u1ebfn \u0111\u1ed5i c\u1ee7a \u0111i\u1ec1u ki\u1ec7n b\u1ec1 m\u1eb7t \u2014 lu\u00f4n x\u00e1c nh\u1eadn b\u1eb1ng ki\u1ec3m tra m\u00f4-men xo\u1eafn tr\u00ean c\u00e1c m\u1ed1i n\u1ed1i quan tr\u1ecdng.<\/p>\n<hr \/>\n<h2>Xu h\u01b0\u1edbng t\u01b0\u01a1ng lai c\u1ee7a \u1ed1c v\u00edt th\u00e9p kh\u00f4ng g\u1ec9 (2026 tr\u1edf \u0111i)<\/h2>\n<p>Th\u1ecb tr\u01b0\u1eddng s\u1ea3n ph\u1ea9m bu l\u00f4ng A2 70 \u0111ang ph\u00e1t tri\u1ec3n song song v\u1edbi c\u00e1c xu h\u01b0\u1edbng r\u1ed9ng l\u1edbn h\u01a1n v\u1ec1 b\u1ec1n v\u1eefng, khu v\u1ef1c h\u00f3a chu\u1ed7i cung \u1ee9ng, v\u00e0 s\u1ed1 h\u00f3a mua s\u1eafm c\u00f4ng nghi\u1ec7p.<\/p>\n<h3>B\u1ec1n v\u1eefng v\u00e0 N\u1ed9i dung t\u00e1i ch\u1ebf<\/h3>\n<p>Th\u00e9p kh\u00f4ng g\u1ec9 l\u00e0 m\u1ed9t trong nh\u1eefng v\u1eadt li\u1ec7u \u0111\u01b0\u1ee3c t\u00e1i ch\u1ebf nhi\u1ec1u nh\u1ea5t tr\u00ean tr\u00e1i \u0111\u1ea5t \u2014 t\u1ef7 l\u1ec7 n\u1ed9i dung t\u00e1i ch\u1ebf trung b\u00ecnh to\u00e0n c\u1ea7u trong s\u1ea3n xu\u1ea5t 304\/316 hi\u1ec7n nay v\u01b0\u1ee3t qu\u00e1 60% \u1edf nhi\u1ec1u th\u1ecb tr\u01b0\u1eddng, v\u00e0 m\u1ed9t s\u1ed1 nh\u00e0 m\u00e1y \u0111\u1eb7c bi\u1ec7t b\u00e1o c\u00e1o tr\u00ean 80%. \u0110\u00e2y ng\u00e0y c\u00e0ng tr\u1edf th\u00e0nh y\u1ebfu t\u1ed1 quy\u1ebft \u0111\u1ecbnh trong ti\u00eau chu\u1ea9n: c\u00e1c ki\u1ebfn tr\u00fac s\u01b0 v\u00e0 k\u1ef9 s\u01b0 l\u00e0m vi\u1ec7c theo c\u00e1c khung LEED v4.1 ho\u1eb7c BREEAM c\u00f3 th\u1ec3 nh\u1eadn \u0111i\u1ec3m v\u1eadt li\u1ec7u b\u1eb1ng c\u00e1ch ch\u1ec9 \u0111\u1ecbnh c\u00e1c lo\u1ea1i \u1ed1c v\u00edt c\u00f3 n\u1ed9i dung t\u00e1i ch\u1ebf \u0111\u00e3 \u0111\u01b0\u1ee3c ch\u1ee9ng minh v\u00e0 Tuy\u00ean b\u1ed1 S\u1ea3n ph\u1ea9m M\u00f4i tr\u01b0\u1eddng (EPDs).<\/p>\n<p>Theo <a href=\"https:\/\/www.worldstainless.org\/sustainability\/\" target=\"_blank\" rel=\"noopener\">b\u00e1o c\u00e1o b\u1ec1n v\u1eefng n\u0103m 2024 c\u1ee7a H\u1ed9i \u0111\u1ed3ng Th\u00e9p Kh\u00f4ng G\u1ec9 Qu\u1ed1c t\u1ebf (International Stainless Steel Forum)<\/a>, n\u0103ng l\u1ef1c s\u1ea3n xu\u1ea5t th\u00e9p to\u00e0n c\u1ea7u d\u1ef1 ki\u1ebfn s\u1ebd t\u0103ng 15% v\u00e0o n\u0103m 2030, v\u1edbi c\u00e1c b\u1ed5 sung c\u00f4ng su\u1ea5t \u0111\u00e1ng k\u1ec3 t\u1ea1i \u1ea4n \u0110\u1ed9 v\u00e0 \u0110\u00f4ng Nam \u00c1, \u0111i\u1ec1u n\u00e0y s\u1ebd ti\u1ebfp t\u1ee5c gi\u1ea3m chi ph\u00ed c\u1ee7a c\u00e1c lo\u1ea1i bu l\u00f4ng A2-grade so v\u1edbi c\u00e1c l\u1ef1a ch\u1ecdn th\u00e9p carbon. Xu h\u01b0\u1edbng gi\u00e1 d\u00e0i h\u1ea1n \u1ee7ng h\u1ed9 vi\u1ec7c m\u1edf r\u1ed9ng ti\u00eau chu\u1ea9n bu l\u00f4ng A2 70 ngay c\u1ea3 trong c\u00e1c \u1ee9ng d\u1ee5ng x\u00e2y d\u1ef1ng nh\u1ea1y c\u1ea3m v\u1ec1 gi\u00e1 c\u1ea3.<\/p>\n<h3>C\u00f4ng nghi\u1ec7p 4.0: \u0110\u00e1nh d\u1ea5u k\u1ef9 thu\u1eadt s\u1ed1 v\u00e0 G\u1eafn k\u1ebft th\u00f4ng minh<\/h3>\n<p><strong>M\u00e3 QR \u0111\u00e1nh d\u1ea5u laser v\u00e0 c\u00e1c k\u00fd hi\u1ec7u DMC (Data Matrix Code) tr\u00ean \u0111\u1ea7u bu l\u00f4ng ri\u00eang l\u1ebb<\/strong> \u0111ang b\u1eaft \u0111\u1ea7u xu\u1ea5t hi\u1ec7n trong c\u00e1c \u1ee9ng d\u1ee5ng c\u00f3 gi\u00e1 tr\u1ecb cao (ngo\u00e0i kh\u01a1i, h\u00e0ng kh\u00f4ng v\u0169 tr\u1ee5, h\u1ea1t nh\u00e2n). Qu\u00e9t \u0111\u1ea7u bu l\u00f4ng li\u00ean k\u1ebft tr\u1ef1c ti\u1ebfp v\u1edbi ch\u1ee9ng ch\u1ec9 v\u1eadt li\u1ec7u, l\u00f4 nhi\u1ec7t, v\u00e0 b\u00e1o c\u00e1o th\u1eed nghi\u1ec7m c\u01a1 h\u1ecdc \u2014 kh\u1ea3 n\u0103ng truy xu\u1ea5t ngu\u1ed3n g\u1ed1c \u0111\u1ea7y \u0111\u1ee7 m\u00e0 kh\u00f4ng c\u1ea7n h\u1ed3 s\u01a1 gi\u1ea5y.<\/p>\n<p>\u0110\u1ed1i v\u1edbi th\u1ecb tr\u01b0\u1eddng x\u00e2y d\u1ef1ng v\u00e0 c\u00f4ng nghi\u1ec7p chung ph\u1ee5c v\u1ee5 c\u00e1c s\u1ea3n ph\u1ea9m bu l\u00f4ng A2 70, xu h\u01b0\u1edbng n\u00e0y c\u00f2n \u0111ang trong giai \u0111o\u1ea1n \u0111\u1ea7u nh\u01b0ng \u0111\u00e1ng \u0111\u1ec3 theo d\u00f5i. C\u00e1c nh\u00f3m mua h\u00e0ng x\u1eed l\u00fd c\u00e1c lo\u1ea1i \u1ed1c v\u00edt gi\u1ea3 m\u1ea1o (m\u1ed9t v\u1ea5n \u0111\u1ec1 \u0111\u00e3 \u0111\u01b0\u1ee3c ghi nh\u1eadn trong c\u00e1c lo\u1ea1i th\u00e9p kh\u00f4ng g\u1ec9 \u2014 h\u00e0ng gi\u1ea3 A4-70 \u0111\u01b0\u1ee3c cung c\u1ea5p d\u01b0\u1edbi d\u1ea1ng A2-70, ho\u1eb7c A2-50 b\u1ecb ghi nh\u1ea7m th\u00e0nh A2-70) c\u00f3 kh\u1ea3 n\u0103ng s\u1ebd th\u00fac \u0111\u1ea9y vi\u1ec7c s\u1eed d\u1ee5ng \u0111\u00e1nh d\u1ea5u k\u1ef9 thu\u1eadt s\u1ed1 nh\u01b0 ti\u00eau chu\u1ea9n trong v\u00f2ng 5 n\u0103m.<\/p>\n<p>Ch\u1ec9 th\u1ecb l\u1ef1c xo\u1eafn qua v\u00f2ng \u0111\u1ec7m m\u00e0u ho\u1eb7c ch\u1ec9 th\u1ecb ho\u00e1 h\u1ecdc thay \u0111\u1ed5i m\u00e0u t\u1ea1i \u0111i\u1ec3m m\u1ee5c ti\u00eau <a href=\"https:\/\/productionscrews.com\/vi\/essential-guide-to-fastener-installation-why-clamp-load-beats-torque-every-time\/\" target=\"_blank\" rel=\"noopener\" data-wpil-monitor-id=\"822\">l\u1ef1c k\u1eb9p<\/a> c\u0169ng ng\u00e0y c\u00e0ng ph\u1ed5 bi\u1ebfn trong c\u00e1c l\u1eafp \u0111\u1eb7t y\u00eau c\u1ea7u ch\u1ea5t l\u01b0\u1ee3ng cao \u2014 lo\u1ea1i b\u1ecf s\u1ef1 suy \u0111o\u00e1n trong qu\u00e1 tr\u00ecnh l\u1eafp \u0111\u1eb7t.<\/p>\n<hr \/>\n<h2>C\u00e1c c\u00e2u h\u1ecfi th\u01b0\u1eddng g\u1eb7p<\/h2>\n<h3>A2-70 c\u00f3 ngh\u0129a l\u00e0 g\u00ec tr\u00ean m\u1ed9t chi\u1ebfc bu-l\u00f4ng?<\/h3>\n<p>A2-70 c\u00f3 ngh\u0129a l\u00e0 <a href=\"https:\/\/productionscrews.com\/vi\/stainless-steel-bolts\/\" target=\"_blank\" rel=\"noopener\" data-wpil-monitor-id=\"820\">bu l\u00f4ng \u0111\u01b0\u1ee3c l\u00e0m t\u1eeb th\u00e9p kh\u00f4ng g\u1ec9 c\u1ea5p austenitic<\/a> A2 (t\u01b0\u01a1ng \u0111\u01b0\u01a1ng v\u1edbi th\u00e9p kh\u00f4ng g\u1ec9 304) v\u00e0 \u0111\u00e3 \u0111\u1ea1t \u0111\u01b0\u1ee3c l\u1edbp t\u00ednh ch\u1ea5t 70, ngh\u0129a l\u00e0 \u0111\u1ed9 b\u1ec1n k\u00e9o t\u1ed1i thi\u1ec3u 700 N\/mm\u00b2 v\u00e0 gi\u1edbi h\u1ea1n ch\u1ecbu t\u1ea3i t\u1ed1i thi\u1ec3u 450 N\/mm\u00b2. N\u00f3 \u0111\u01b0\u1ee3c \u0111\u00e1nh d\u1ea5u nh\u01b0 v\u1eady theo ISO 3506.<\/p>\n<h3>Ti\u00eau chu\u1ea9n t\u01b0\u01a1ng \u0111\u01b0\u01a1ng c\u1ee7a ASTM v\u1edbi A2-70 l\u00e0 g\u00ec?<\/h3>\n<p>Ti\u00eau chu\u1ea9n ASTM g\u1ea7n nh\u1ea5t cho m\u1ed9t chi\u1ebfc bu-l\u00f4ng A2-70 l\u00e0 <strong>Nh\u00f3m h\u1ee3p kim ASTM F593 1 (th\u00e9p kh\u00f4ng g\u1ec9 304\/305), T\u00ecnh tr\u1ea1ng CW<\/strong> (gia c\u00f4ng l\u1ea1nh). T\u00ecnh tr\u1ea1ng CW cung c\u1ea5p m\u1ee9c \u0111\u1ed9 c\u01b0\u1eddng \u0111\u1ed9 t\u01b0\u01a1ng \u0111\u01b0\u01a1ng v\u1edbi l\u1edbp t\u00ednh ch\u1ea5t 70 c\u1ee7a ti\u00eau chu\u1ea9n ISO 3506. L\u01b0u \u00fd r\u1eb1ng ch\u1ee9ng nh\u1eadn ASTM v\u00e0 ISO kh\u00f4ng th\u1ec3 ho\u00e1n \u0111\u1ed5i tr\u1ef1c ti\u1ebfp \u2014 \u0111\u1ed1i v\u1edbi c\u00e1c \u1ee9ng d\u1ee5ng quan tr\u1ecdng, x\u00e1c nh\u1eadn ti\u00eau chu\u1ea9n y\u00eau c\u1ea7u v\u00e0 l\u1ea5y c\u00e1c bu-l\u00f4ng \u0111\u01b0\u1ee3c ch\u1ee9ng nh\u1eadn ph\u00f9 h\u1ee3p ti\u00eau chu\u1ea9n \u0111\u00f3.<\/p>\n<h3>T\u00f4i c\u00f3 th\u1ec3 s\u1eed d\u1ee5ng bu-l\u00f4ng A2-70 v\u1edbi \u0111ai \u1ed1c th\u00e9p kh\u00f4ng g\u1ec9 kh\u00f4ng?<\/h3>\n<p>C\u00f3 \u2014 v\u00e0 b\u1ea1n n\u00ean l\u00e0m v\u1eady. S\u1eed d\u1ee5ng \u0111ai \u1ed1c A2 v\u1edbi bu-l\u00f4ng A2-70 \u0111\u1ec3 \u0111\u1ea3m b\u1ea3o t\u01b0\u01a1ng th\u00edch. C\u00e1c lo\u1ea1i c\u1ea5p kh\u00e1c nhau (v\u00ed d\u1ee5, \u0111ai \u1ed1c A4 tr\u00ean bu-l\u00f4ng A2) th\u01b0\u1eddng ch\u1ea5p nh\u1eadn \u0111\u01b0\u1ee3c v\u1ec1 m\u1eb7t ch\u1ed1ng \u0103n m\u00f2n nh\u01b0ng kh\u00f4ng theo ti\u00eau chu\u1ea9n v\u00e0 c\u00f3 th\u1ec3 g\u00e2y ra v\u1ea5n \u0111\u1ec1 v\u1ec1 t\u00e0i li\u1ec7u cho c\u00e1c b\u1ed9 l\u1eafp r\u00e1p quan tr\u1ecdng v\u1ec1 ch\u1ea5t l\u01b0\u1ee3ng. Lu\u00f4n s\u1eed d\u1ee5ng ch\u1ea5t ch\u1ed1ng d\u00ednh ho\u1eb7c d\u1ea7u b\u00f4i tr\u01a1n ren khi l\u1eafp r\u00e1p ren th\u00e9p kh\u00f4ng g\u1ec9 \u0111\u1ec3 tr\u00e1nh hi\u1ec7n t\u01b0\u1ee3ng galled.<\/p>\n<h3>Bu-l\u00f4ng A2-70 c\u00f3 t\u1eeb t\u00ednh kh\u00f4ng?<\/h3>\n<p>Kh\u00f4ng. Th\u00e9p kh\u00f4ng g\u1ec9 A2 l\u00e0 d\u1ea1ng austenitic v\u00e0 <strong>kh\u00f4ng t\u1eeb t\u00ednh trong tr\u1ea1ng th\u00e1i annealed<\/strong>. Tuy nhi\u00ean, qu\u00e1 tr\u00ecnh gia c\u00f4ng l\u1ea1nh trong qu\u00e1 tr\u00ecnh s\u1ea3n xu\u1ea5t bu-l\u00f4ng A2-70 c\u00f3 th\u1ec3 t\u1ea1o ra m\u1ed9t l\u01b0\u1ee3ng nh\u1ecf martensite trong c\u1ea5u tr\u00fac vi m\u00f4, khi\u1ebfn bu-l\u00f4ng y\u1ebfu t\u1eeb t\u00ednh nh\u1eb9. \u0110i\u1ec1u n\u00e0y l\u00e0 b\u00ecnh th\u01b0\u1eddng v\u00e0 kh\u00f4ng bi\u1ec3u th\u1ecb l\u1ed7i v\u1eadt li\u1ec7u. Th\u00e9p kh\u00f4ng g\u1ec9 t\u1eeb t\u00ednh th\u1ef1c s\u1ef1 (c\u00e1c lo\u1ea1i ferritic ho\u1eb7c martensitic) tr\u00f4ng kh\u00e1c bi\u1ec7t \u2014 n\u1ebfu b\u1ea1n c\u1ea7n c\u00e1c b\u1ed9 ph\u1eadn kh\u00f4ng t\u1eeb t\u00ednh x\u00e1c nh\u1eadn, h\u00e3y ch\u1ec9 \u0111\u1ecbnh A2 ho\u1eb7c A4 v\u00e0 x\u00e1c nh\u1eadn v\u1edbi nh\u00e0 cung c\u1ea5p.<\/p>\n<h3>K\u00edch th\u01b0\u1edbc m\u0169i khoan ph\u00f9 h\u1ee3p cho bu-l\u00f4ng A2-70 M8 l\u00e0 g\u00ec?<\/h3>\n<p>\u0110\u1ed1i v\u1edbi l\u1ed7 khoan \u0111\u1ec3 l\u1eafp qua t\u1ea5m (k\u1ebft h\u1ee3p trung b\u00ecnh theo ISO 273): <strong>M\u0169i khoan 9.0 mm<\/strong>. \u0110\u1ec3 ren l\u1ed7 khoan \u00e2m \u0111\u1ec3 l\u1eafp v\u00edt M8: <strong>M\u0169i khoan 6.8 mm<\/strong> cho ren M8\u00d71.25 ti\u00eau chu\u1ea9n th\u00f4. S\u1eed d\u1ee5ng m\u0169i khoan ph\u1ee7 cobalt ho\u1eb7c TiN khi khoan v\u00e0o th\u00e9p kh\u00f4ng g\u1ec9, v\u00e0 s\u1eed d\u1ee5ng ch\u1ea5t l\u00e0m m\u00e1t c\u1eaft.<\/p>\n<h3>Bu-l\u00f4ng A2-70 m\u1ea1nh h\u01a1n so v\u1edbi Grade 8.8 bao nhi\u00eau?<\/h3>\n<p>M\u1ed9t chi\u1ebfc bu-l\u00f4ng A2-70 c\u00f3 \u0111\u1ed9 b\u1ec1n k\u00e9o 700 N\/mm\u00b2 so v\u1edbi 800 N\/mm\u00b2 c\u1ee7a th\u00e9p carbon Grade 8.8 \u2014 y\u1ebfu h\u01a1n kho\u1ea3ng 12.5% v\u1ec1 m\u1eb7t k\u00e9o. L\u1ef1c ch\u1ecbu \u0111\u1ef1ng (t\u01b0\u01a1ng \u0111\u01b0\u01a1ng gi\u1edbi h\u1ea1n ch\u1ea3y) l\u00e0 450 N\/mm\u00b2 cho A2-70 so v\u1edbi 640 N\/mm\u00b2 cho 8.8 \u2014 ch\u00eanh l\u1ec7ch \u0111\u00e1ng k\u1ec3 30%. \u0110\u1ed1i v\u1edbi c\u00e1c m\u1ed1i n\u1ed1i ch\u1ecbu t\u1ea3i m\u00e0 kh\u00f4ng y\u00eau c\u1ea7u ch\u1ed1ng \u0103n m\u00f2n, th\u00e9p carbon 8.8 l\u00e0 l\u1ef1a ch\u1ecdn m\u1ea1nh h\u01a1n v\u00e0 ti\u1ebft ki\u1ec7m h\u01a1n. Trong m\u00f4i tr\u01b0\u1eddng \u0103n m\u00f2n, tu\u1ed5i th\u1ecd kh\u00f4ng c\u1ea7n b\u1ea3o tr\u00ec c\u1ee7a A2-70 th\u01b0\u1eddng \u0111\u1ee7 \u0111\u1ec3 \u0111\u00e1p \u1ee9ng y\u00eau c\u1ea7u.<\/p>\n<h3>T\u00f4i c\u00f3 th\u1ec3 mua bu-l\u00f4ng A2-70 \u1edf \u0111\u00e2u?<\/h3>\n<p>Bu l\u00f4ng A2-70 c\u00f3 s\u1eb5n t\u1eeb c\u00e1c nh\u00e0 ph\u00e2n ph\u1ed1i \u1ed1c v\u00edt c\u00f4ng nghi\u1ec7p, nh\u00e0 cung c\u1ea5p tr\u1ef1c tuy\u1ebfn v\u00e0 c\u00e1c nh\u00e0 s\u1ea3n xu\u1ea5t \u1ed1c v\u00edt th\u00e9p kh\u00f4ng g\u1ec9 chuy\u00ean d\u1ee5ng. Khi mua h\u00e0ng, h\u00e3y t\u00ecm c\u00e1c nh\u00e0 cung c\u1ea5p cung c\u1ea5p ch\u1ee9ng ch\u1ec9 v\u1eadt li\u1ec7u ISO 3506 v\u00e0 x\u00e1c nh\u1eadn c\u00e1c d\u1ea5u hi\u1ec7u tr\u00ean \u0111\u1ea7u ph\u00f9 h\u1ee3p v\u1edbi c\u1ea5p \u0111\u1ed9 \u0111\u1eb7t h\u00e0ng. \u0110\u1ed1i v\u1edbi \u0111\u01a1n h\u00e0ng s\u1ed1 l\u01b0\u1ee3ng l\u1edbn, y\u00eau c\u1ea7u gi\u1ea5y ch\u1ee9ng nh\u1eadn nh\u00e0 m\u00e1y (ch\u1ee9ng ch\u1ec9 EN 10204 3.1 ho\u1eb7c 3.2) \u0111\u1ec3 x\u00e1c minh s\u1ef1 ph\u00f9 h\u1ee3p v\u1ec1 v\u1eadt li\u1ec7u v\u00e0 c\u01a1 kh\u00ed \u2014 \u0111\u00e2y l\u00e0 th\u1ef1c h\u00e0nh ti\u00eau chu\u1ea9n trong b\u1ea5t k\u1ef3 d\u1ef1 \u00e1n n\u00e0o y\u00eau c\u1ea7u ch\u1ea5t l\u01b0\u1ee3ng cao.<\/p>\n<figure><img decoding=\"async\" style=\"width: 100%; height: auto;\" src=\"https:\/\/productionscrews.com\/wp-content\/uploads\/2026\/04\/04-closing-2.jpg\" alt=\"Kho ch\u1ee9a \u1ed1c v\u00edt v\u00e0 bu l\u00f4ng c\u00f4ng nghi\u1ec7p t\u1ea1i c\u01a1 s\u1edf s\u1ea3n xu\u1ea5t DingLong, tr\u01b0ng b\u00e0y kho l\u01b0u tr\u1eef t\u1ed5 h\u1ee3p bu l\u00f4ng m\u1eb7t b\u00edch v\u00e0 \u1ed1c v\u00edt c\u00f4ng nghi\u1ec7p trong m\u1ed9t m\u00f4i tr\u01b0\u1eddng c\u00f4ng nghi\u1ec7p r\u1ed9ng r\u00e3i.\" \/><\/figure>\n<hr \/>\n<h2>K\u1ebft lu\u1eadn<\/h2>\n<p>Bu l\u00f4ng A2-70 l\u00e0 l\u1ef1a ch\u1ecdn ph\u00f9 h\u1ee3p cho ph\u1ea7n l\u1edbn c\u00e1c \u1ee9ng d\u1ee5ng b\u1eaft v\u00edt nh\u1ea1y c\u1ea3m v\u1edbi \u0103n m\u00f2n: x\u00e2y d\u1ef1ng ngo\u00e0i tr\u1eddi, thi\u1ebft b\u1ecb ch\u1ebf bi\u1ebfn th\u1ef1c ph\u1ea9m, ph\u1ea7n c\u1ee9ng ki\u1ebfn tr\u00fac, v\u00e0 b\u1ea5t c\u1ee9 n\u01a1i n\u00e0o b\u1ea1n c\u1ea7n m\u1ed9t lo\u1ea1i \u1ed1c v\u00edt v\u1eabn c\u00f3 th\u1ec3 ho\u1ea1t \u0111\u1ed9ng sau 20 n\u0103m m\u00e0 kh\u00f4ng c\u1ea7n b\u1ea3o tr\u00ec. S\u1ef1 k\u1ebft h\u1ee3p gi\u1eefa v\u1eadt li\u1ec7u th\u00e9p kh\u00f4ng g\u1ec9 t\u01b0\u01a1ng \u0111\u01b0\u01a1ng 304 v\u00e0 \u0111\u1ed9 b\u1ec1n l\u00e0m vi\u1ec7c l\u1ea1nh 700 N\/mm\u00b2 bao ph\u1ee7 ph\u1ea7n l\u1edbn c\u00e1c y\u00eau c\u1ea7u th\u1ef1c t\u1ebf.<\/p>\n<p>C\u00e1c \u0111i\u1ec3m quy\u1ebft \u0111\u1ecbnh ch\u00ednh: n\u00e2ng c\u1ea5p l\u00ean A4-80 n\u1ebfu \u0103n m\u00f2n do chloride l\u00e0 y\u1ebfu t\u1ed1 m\u00f4i tr\u01b0\u1eddng th\u1ef1c s\u1ef1, v\u00e0 kh\u00f4ng bao gi\u1edd ch\u1ea5p nh\u1eadn A2-50 l\u00e0m thay th\u1ebf khi \u0111\u00e3 ch\u1ec9 \u0111\u1ecbnh A2-70 \u2014 ch\u00fang tr\u00f4ng gi\u1ed1ng nhau nh\u01b0ng c\u00f3 \u0111\u1eb7c t\u00ednh c\u01a1 h\u1ecdc kh\u00e1c bi\u1ec7t r\u00f5 r\u00e0ng. Khi l\u1eafp \u0111\u1eb7t, vi\u1ec7c ng\u0103n ng\u1eeba g\u1ec9 s\u00e9t b\u1eb1ng ch\u1ea5t b\u00f4i tr\u01a1n ren l\u00e0 th\u1ef1c h\u00e0nh quan tr\u1ecdng nh\u1ea5t m\u00e0 h\u1ea7u h\u1ebft c\u00e1c h\u01b0\u1edbng d\u1eabn l\u1eafp \u0111\u1eb7t b\u1ecf qua. <a href=\"https:\/\/productionscrews.com\/vi\/rivet-nut\/\" target=\"_blank\" rel=\"noopener\" data-wpil-monitor-id=\"823\">h\u01b0\u1edbng d\u1eabn l\u1eafp \u0111\u1eb7t<\/a> b\u1ecf qua.<\/p>\n<p>T\u1ea1i ProductionScrews.com, ch\u00fang t\u00f4i l\u01b0u kho c\u00e1c b\u1ed9 bu l\u00f4ng A2-70 v\u1edbi t\u1ea5t c\u1ea3 c\u00e1c ki\u1ec3u \u0111\u1ea7u ch\u00ednh, t\u1eeb M4 \u0111\u1ebfn M36, v\u1edbi ch\u1ee9ng nh\u1eadn ISO 3506 \u0111\u1ea7y \u0111\u1ee7 theo y\u00eau c\u1ea7u. Duy\u1ec7t qua d\u00f2ng s\u1ea3n ph\u1ea9m A2-70 c\u1ee7a ch\u00fang t\u00f4i ho\u1eb7c li\u00ean h\u1ec7 \u0111\u1ed9i ng\u0169 k\u1ef9 thu\u1eadt n\u1ebfu b\u1ea1n c\u1ea7n gi\u00fap \u0111\u1ee1 trong vi\u1ec7c ch\u1ecdn lo\u1ea1i bu l\u00f4ng ph\u00f9 h\u1ee3p v\u1edbi \u1ee9ng d\u1ee5ng.<\/p>\n<p><script type=\"application\/ld+json\">{\n    \"@context\": \"https:\\\/\\\/schema.org\",\n    \"@type\": \"FAQPage\",\n    \"mainEntity\": [\n        {\n            \"@type\": \"Question\",\n            \"name\": \"What does A2-70 mean on a bolt?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"A2-70 means the bolt is made from austenitic stainless steel grade A2 (equivalent to 304 stainless) and has achieved property class 70, meaning a minimum tensile strength of 700 N\\\/mm\\u00b2 and a minimum proof stress of 450 N\\\/mm\\u00b2, per ISO 3506.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"What is the ASTM equivalent of A2-70?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"The closest ASTM equivalent for an A2-70 bolt is ASTM F593 Alloy Group 1 (304\\\/305 stainless), Condition CW (cold worked), which provides comparable strength to ISO 3506 class 70.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"Can I use A2-70 bolts with a stainless steel nut?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"Yes. Use A2 nuts with A2-70 bolts. Always apply anti-seize or thread lubricant when assembling stainless-to-stainless threads to prevent galling.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"Is an A2-70 bolt magnetic?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"No, A2-70 bolts are non-magnetic in the annealed state. Minor magnetism from cold working during manufacture is normal and not a material defect.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"What drill bit size for an A2-70 M8 bolt?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"For a clearance hole (medium fit per ISO 273): 9.0 mm. For threading a blind hole (M8\\u00d71.25 coarse thread): 6.8 mm tap drill bit. Use cobalt or TiN-coated bits with cutting fluid when drilling stainless.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"How strong is an A2-70 bolt compared to Grade 8.8?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"An A2-70 bolt has 700 N\\\/mm\\u00b2 tensile strength vs. 800 N\\\/mm\\u00b2 for 8.8 carbon steel \\u2014 about 12.5% weaker in tensile terms. For non-corrosive environments, 8.8 steel is stronger and more economical; for corrosive environments, A2-70's maintenance-free service life justifies the specification.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"Where can I buy A2-70 bolts?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"A2-70 bolts are available from industrial fastener distributors and specialist stainless fastener suppliers. Always request ISO 3506 material certificates and confirm head markings match the ordered grade. For bulk orders, request an EN 10204 3.1 or 3.2 mill certificate.\"\n            }\n        }\n    ]\n}<\/script><\/p>","protected":false},"excerpt":{"rendered":"<p>M\u1ecdi \u0111i\u1ec1u b\u1ea1n c\u1ea7n bi\u1ebft v\u1ec1 \u1ed1c v\u00edt A2-70: ph\u00e2n t\u00edch k\u00fd hi\u1ec7u, \u0111\u1eb7c t\u00ednh v\u1eadt li\u1ec7u, c\u00e1c lo\u1ea1i, \u1ee9ng d\u1ee5ng, gi\u00e1 tr\u1ecb m\u00f4-men xo\u1eafn, k\u00edch th\u01b0\u1edbc khoan, v\u00e0 c\u00e1ch ch\u1ecdn gi\u1eefa A2-70 v\u00e0 A4-80.<\/p>","protected":false},"author":1,"featured_media":3459,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-3463","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-screws-flange-tutorial"],"_links":{"self":[{"href":"https:\/\/productionscrews.com\/vi\/wp-json\/wp\/v2\/posts\/3463","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/productionscrews.com\/vi\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/productionscrews.com\/vi\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/productionscrews.com\/vi\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/productionscrews.com\/vi\/wp-json\/wp\/v2\/comments?post=3463"}],"version-history":[{"count":1,"href":"https:\/\/productionscrews.com\/vi\/wp-json\/wp\/v2\/posts\/3463\/revisions"}],"predecessor-version":[{"id":3464,"href":"https:\/\/productionscrews.com\/vi\/wp-json\/wp\/v2\/posts\/3463\/revisions\/3464"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/productionscrews.com\/vi\/wp-json\/wp\/v2\/media\/3459"}],"wp:attachment":[{"href":"https:\/\/productionscrews.com\/vi\/wp-json\/wp\/v2\/media?parent=3463"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/productionscrews.com\/vi\/wp-json\/wp\/v2\/categories?post=3463"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/productionscrews.com\/vi\/wp-json\/wp\/v2\/tags?post=3463"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}