What Makes High Quality Spring Wire?

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Allan, what makes a great quality wire product? 

To me that can be answered simply and in one word….CONSISTENCY.  

However, manufacturing consistent wire isn’t easy. To keep the wire consistent, you need to control numerous characteristics.  

I’ll break that down into 3 key characteristics. 

The Three Key Wire Characteristics Necessary to Provide Consistent Spring Wire 

1. Control the diameter of the wire. At the spring coiler, most springs these days are coiled on a coiling point, much like how one would curl a ribbon with scissors. Wire hits the point and coils. If the diameter of the wire varies, the spring coil will most likely vary as well. Spring makers also try and hold various characteristics of the springs: free length of the spring, ID and OD of the spring and the pitch. Rejections from spring manufacturers often state that they can’t hold free length or ID varies. Diameter inconsistencies could be the cause. 

2. Control the consistency of the wire coating. With certain types of wire, controlling the consistency of the coating is most important, especially on the stainless side. Common rejections are often due to complaints of hard and soft spots. Any wire salesperson has heard about this type of rejection. When you hear about hard and soft spots, you would certainly think that the hardness or the tensile of the wire is varying causing the springs to vary. Sure, that could happen I suppose, but considering the processing of wire, something real crazy would need to happen in  to have this type of effect. One just does not see tensile varying enough that it could cause spring variation. My thinking is much more in line with the potential of the coating varying, making it feel like hard and soft spots at the coiling point.  Consider soap coating on stainless spring wire. Soap coatings vary between mills, but basically the soap coating is made up a non-metallic coating that is put on at a process size, plus the die soap used during the drawing stage. So in my opinion, it is more difficult to control the consistency of the soap coatings simply due to the process. This is why a lot of spring coilers prefer the nickel coated product versus the soap coat, especially in the finer diameter sizes (under .040”). Nickel is not a good lubricant, but it does help to keep the coating more consistent during the wire drawing and spring coiling processes.  

3. Control of cast and helix of the spring wire. This is another wire characteristic very important at the spring coiler, especially if coiled on a point. Back in my NS days, we spent a lot of time testing coils of wire that ran well versus coils of wire that saw variation at the spring coiler. I remember tearing a coil apart every 2 lbs to check the cast and helix. One set of coils was produced by a Japanese competitor and one set was produced at NS. The competitor’s wire was nickel coated; our wire was copper coated. Throughout the coil, our competitor’s coils did not vary at all in cast and helix. Our coils had extreme variation. I think what happens if the cast or helix varies enough during the spring coiling process, it will vary its angle into the coiling point, causing the actual coil to vary. So, it is not so much what the cast and helix measures at the start of the coil, but whether it stays consistent throughout the coil.  

To sum, controlling the consistency of the wire diameter, wire coating, and the wire’s cast and helix will result in a pretty high quality spring wire product!  

-Allan Osos, Vice President, Gibbs Interwire & Steel LLC

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Gibbs Interwire knows quality wire. 

Gibbs Interwire maintains long-term relationships (since 1956!) with the highest quality wire mills.  We invite you to contact us and let us show you how our wire can improve your products and processes. 

Gibbs Interwire Capabilities 

0.001” to 0.875” (0.0254mm to 22.225mm)

Nickel Wire Alloys