Ultimate Guide to Spring Clip Production: Materials, Steps & Quality Control

How to Make Spring Clips: A Complete Guide

Why Spring Clips Matter

Spring clips are small metal pieces that hold things together. You can find them in cars, computers, and many everyday items. They might look simple, but making them requires careful planning and precise work. If any step goes wrong, the clip might break or not work properly. This guide explains how spring clips are made, breaking down each step so you can understand the complete process.

Making a spring clip involves several carefully controlled steps. Each step affects how well the final product works. We will look at:

• Choosing Materials: The Starting Point for Quality
• Main Manufacturing Steps: Shaping the Clip
• Important Finishing Steps: Making It Last Longer
• Quality Checks: Making Sure It Works Right

Understanding these basics is important for anyone who needs to design, buy, or make parts that must work reliably.

Starting Point: Choosing Materials

Picking the right material is the most important decision in spring clip production. The material determines how strong the clip will be, how well it resists damage from weather or chemicals, and how much it costs. This choice isn’t random – it’s a careful engineering decision based on what the clip needs to do. Choosing the wrong material can cause the clip to break too soon, lose its grip, or rust. Let’s look at the main types of materials used.

High-carbon steels, like AISI 1075 and 1095, are the most commonly used materials. They offer great strength, last a long time, and don’t cost much. This makes them perfect for making large quantities of clips that will be used inside cars or for general fastening jobs where rust isn’t a big concern. These materials don’t naturally act like springs – they need special heat treatment after being shaped to develop their spring properties.

Stainless steels are used when the clip needs to resist rust and corrosion. Types like 301, 302, and 304 resist corrosion well and can be shaped easily. For jobs that need higher strength and better spring action, special grades like 17-7 PH are used. These materials are common in medical equipment, outdoor gear, and food processing machines where both strength and cleanliness are essential.

Copper alloys are chosen when the clip needs to conduct electricity or heat well while still acting like a spring. Beryllium Copper (BeCu), specifically Alloy 25, is special because it combines high strength (similar to steel), excellent electrical conductivity, and won’t create sparks or be affected by magnets. This makes it perfect for electrical connectors, battery contacts, and parts used in dangerous environments. Phosphor Bronze is another option that conducts electricity well and resists corrosion at a lower cost than BeCu, making it suitable for less demanding electrical contacts and switches.

Main Manufacturing Steps

Once the material is chosen, it must be shaped into the desired form. The choice of manufacturing method depends on how complex the part is, how many need to be made, how much the tooling costs, and how efficiently the material can be used. The two main methods for spring clip production are power press stamping and fourslide/multislide forming. Understanding how these work, their advantages, and their limitations is important for designing parts that can be made efficiently and cost-effectively.

Power Press Stamping

Power press stamping is a high-speed manufacturing process that works best for making flat or simple three-dimensional parts in very large quantities. The key to this process is the progressive die, a complex and strong tool set that fits into a mechanical or hydraulic press.

The process starts with a coil of raw material strip fed into the press. As the strip moves through the die with each press stroke, different operations happen in sequence at different stations within the tool. These operations can include:

1. Piercing: Punching holes or slots into the strip.
2. Blanking: Cutting the outer shape of the part from the strip, while it’s still attached to the carrier strip.
3. Forming: Bending or shaping the part into its three-dimensional form.
4. Cut-off: Separating the finished part from the carrier strip.

The main advantage of stamping is its incredible speed. Modern presses can run at hundreds of strokes per minute, making multiple parts with each stroke. This makes each part very cheap when making large quantities (typically over 100,000 pieces). However, designing and building a progressive die costs a lot of money upfront, and it takes a long time to make the tooling. Also, complex shapes with bends greater than 90 degrees or features on multiple levels can be difficult or impossible to create efficiently. The process also creates waste material in the form of a “skeleton” or carrier strip, leading to less efficient material use compared to other methods.

Fourslide or Multislide Forming

Fourslide, or multislide, forming is a more flexible process that excels at creating complex, three-dimensional parts with multiple bends. Unlike a power press with one vertical ram, a fourslide machine uses four or more tool slides arranged at 90 degrees to each other, moving horizontally. These slides are driven by cams, allowing for complex and precisely timed tool movements.

The process typically starts with wire or a narrow strip of material fed from a coil. The material is fed into the machine, where it’s first cut to a precise length. Then, the central tool, or “king post,” holds the blank in place while the surrounding tools, mounted on the slides, move in sequence to form the material around the king post. This coordinated, multi-directional action allows for creating bends, twists, and complex shapes that would be impossible with a standard progressive die.

The key advantages of fourslide forming are its ability to produce highly complex parts and its excellent material efficiency, as it often forms the part directly from wire or narrow strip with very little waste. Tooling is generally less expensive and faster to produce than complex progressive dies. This makes the process economically viable for a wide range of production volumes, from short runs to millions of pieces. The setup time is also typically shorter, offering greater flexibility for manufacturers.

Important Finishing Steps

A spring clip isn’t finished once it leaves the press or fourslide machine. The forming process leaves the material in a soft state. To develop the necessary spring characteristics and ensure long-term durability, the parts must undergo critical secondary operations, primarily heat treatment and surface finishing. These steps aren’t optional – they’re essential to transforming a formed piece of metal into a functional engineering component.

Heat Treatment

Heat treatment is a controlled heating and cooling process used to change the internal structure of the material, achieving the desired mechanical properties of hardness, flexibility, and springiness. The specific process depends on the material.

For high-carbon steels, a two-stage process of quenching and tempering is common. First, the parts are heated to a high temperature – for AISI 1075 steel, this is typically around 815°C (1500°F). They are then rapidly cooled, or “quenched,” in oil, water, or special polymer. This rapid cooling creates a hard, brittle structure. The parts are then “tempered” by reheating them to a lower temperature, generally between 315-540°C (600-1000°F), and holding them for a specific time. Tempering relieves internal stresses and reduces brittleness, resulting in a tough, resilient structure with the desired spring rate and resistance to fatigue. All parameters must be tightly controlled according to standards like ASTM A684 to ensure consistency from part to part.

For precipitation-hardening stainless steels like 17-7 PH, the process involves a solution treatment followed by an aging treatment at a specific temperature to create strengthening phases within the material’s grain structure.

Surface Finishing

Surface finishing is applied after heat treatment to provide protection from rust, reduce friction, improve wear resistance, or enhance appearance. The choice of finish depends on the base material and the application’s service environment.

• Zinc Plating: A common and cost-effective coating for carbon steel parts. A layer of zinc is applied using electricity, acting as a protective barrier against corrosion. Special conversion coatings are often applied over the zinc for added protection and color-coding.
• Phosphate Coating: A chemical process that applies a layer of iron or zinc phosphate to steel parts. It provides moderate corrosion resistance and creates an excellent surface for oil retention or as a primer for painting.
• Passivation: This isn’t a coating but a chemical treatment for stainless steel parts. It removes free iron and other surface contaminants left over from manufacturing and promotes the formation of a protective chromium oxide layer that gives stainless steel its characteristic corrosion resistance.
• Mechanical Plating: A process where parts are tumbled in a barrel with metal powder, glass beads, and special chemicals. It’s used to apply coatings like zinc without the risk of hydrogen embrittlement, a phenomenon that can compromise the integrity of high-hardness heat-treated parts.

Ensuring Production Quality

A spring clip’s reliability isn’t assumed – it’s proven through careful quality control throughout the entire production process. From checking raw materials to testing the final part’s mechanical performance, each step ensures that the finished component meets the engineering specification exactly. For a manufacturer, a strong quality system is the foundation of trust and performance.

The process begins with raw material verification. When materials arrive, certifications are checked against the purchase order to confirm the alloy, condition, and dimensional tolerances. In critical applications, samples may be sent to independent labs to verify chemical composition and mechanical properties.

During production, checks during the process are vital. Operators and quality technicians use measuring tools like calipers and micrometers to monitor critical dimensions at set intervals. For high-volume stamping, automated vision systems can inspect 100% of parts for dimensional accuracy and surface defects in real-time. This prevents the production of large quantities of parts that don’t meet specifications.

After finishing operations, final inspection validates the key performance attributes. Hardness is verified using a Rockwell hardness tester to ensure the heat treatment process was successful. The most critical test for a spring clip is load/deflection testing. A specialized force tester is used to compress or deflect the clip to a specified position and measure the resulting force. This test directly verifies that the clip has the correct “spring rate” and will provide the required clamping force in its application.

An experienced production team also focuses on identifying and preventing common defects. This hands-on expertise is invaluable for maintaining high yields and consistent quality.

Modern Design Advantages

In modern manufacturing, excellence is driven by technology that connects design with physical production. Advanced manufacturers use powerful software tools to optimize spring clip designs for performance and manufacturability long before any steel is cut. This digital-first approach reduces development time, minimizes costly errors, and results in a more reliable final product.

The process begins with Computer-Aided Design (CAD), where the initial 3D model of the spring clip is created. However, the true competitive advantage comes from using Finite Element Analysis (FEA). FEA is a simulation technique that digitally breaks down the CAD model into a mesh of small elements. By applying material properties and virtual loads, engineers can accurately predict how the clip will behave under real-world conditions.

We use FEA to answer critical engineering questions upfront: “Will this clip withstand 100,000 cycles without fatigue failure?” or “Where is the highest stress concentration, and can we reduce it by adding a radius or changing the geometry?” The FEA process is a powerful design-validation loop:

1. A 3D model of the clip is created in CAD.
2. The defined material properties (e.g., modulus of elasticity, tensile strength of AISI 1075) are assigned to the model.
3. Virtual loads and constraints are applied, simulating the forces the clip will experience in its assembly.
4. The software analyzes the model and generates visual results, such as stress maps and deflection plots.
5. Engineers interpret these results to identify high-stress areas or potential failure points and refine the design repeatedly until performance is optimized.

This simulation-driven approach allows for the rapid exploration of multiple design variations without the time and expense of building physical prototypes, dramatically accelerating the time-to-market.

Conclusion: Key Production Points

The production of a high-performance spring clip is a sophisticated combination of material science, precision mechanics, and metallurgical engineering. It’s a process where every stage is critical and interconnected. From the initial selection of an alloy to the final verification of spring rate, a failure in one step compromises the integrity of the entire component.

For engineers, designers, and procurement professionals, a deep technical understanding of this process isn’t just academic – it’s essential for designing, sourcing, and producing parts that are reliable, cost-effective, and fit for purpose.

Key takeaways include:

• Material choice determines the ultimate performance potential of the clip.
• The manufacturing method (stamping vs. fourslide) must align with part complexity and volume.
• Heat treatment isn’t an afterthought; it’s what creates the “spring” in a spring clip.
• Careful quality control, including load testing, is the only way to guarantee reliability.
• Modern simulation tools like FEA reduce design risks and speed up development.

1. ASTM International – Metal Testing & Standards https://www.astm.org/
2. Spring Manufacturers Institute (SMI) https://www.smihq.org/
3. Precision Metalforming Association (PMA) https://www.pma.org/
4. SAE International – Materials & Manufacturing Standards https://www.sae.org/
5. ASM International – Materials & Heat Treatment https://www.asminternational.org/
6. ISO – International Organization for Standardization https://www.iso.org/
7. Society of Manufacturing Engineers (SME) https://www.sme.org/
8. ASME – American Society of Mechanical Engineers https://www.asme.org/
9. NIST – National Institute of Standards and Technology https://www.nist.gov/
10. Fabricators & Manufacturers Association (FMA) https://www.fmanet.org/