8x4mm/10x5mm Multicolor Spiral Stamping Compression Mould Spring Length 15-150mm

The color code indicates the load class of the spring. Yellow is typically the lightest load, followed by Blue, Red, Green, and Brown in increasing load order — a convention widely used in stamping die spring standards. Match the color to the load class specified on your die drawing or to the color of the spring you are replacing. If no drawing is available, measure the existing spring's free length, outer diameter, and wire size, then select the matching color and size from the variant options above.

The two numbers refer to the outer diameter and wire (cross-section) dimension of the spring. The 8×4mm spring has a smaller outer diameter and is suited for tighter spring pockets, while the 10×5mm spring has a larger outer diameter and wire section, providing a higher load capacity for the same free length. Always verify the pocket bore diameter in your die or fixture before selecting a size.

Yes. While these springs are designed and sized for stamping mould applications, they are also commonly used in injection mould ejector return positions and other tooling fixtures where a compact rectangular-wire compression spring is needed. Confirm the pocket dimensions and required load class match your mould specification before installation.

The free length is the uncompressed length of the spring. To find the correct free length for a replacement, measure the existing spring when it is fully relaxed (not installed). For a new die design, the free length is typically specified on the die drawing. This product is available in free lengths from 15mm to 150mm — select the length from the Size variant dropdown that matches your requirement.

The corrosion resistance depends on the surface finish of the specific variant. Please contact us to confirm the surface treatment for the size and color you need. For applications in humid or chemically exposed environments, we recommend confirming the finish specification before ordering.

Fatigue life varies by deflection ratio (how far the spring is compressed relative to its free length) and operating conditions. Rectangular-wire spiral mould springs generally offer longer fatigue life than round-wire springs of equivalent outer diameter because the flat wire section allows more coils in the same length, distributing stress more evenly. For rated cycle life at specific deflection percentages, please contact us to confirm for your chosen variant.

These springs are sold individually — one piece per unit ordered. Simply select the Size (cross-section × free length) and Colour (load class) from the variant options, then set the quantity you need in the cart. This lets you stock exactly the right springs for your die without purchasing assortment packs that may not match your tooling.