Die Springs Compression Mould Spring Light/Medium/Heavy Load Duty OD 8-51mm

Measure the spring pocket bore in your die plate. The spring's outside diameter should be 0.5–1 mm smaller than the pocket bore to allow free movement without binding. For example, if your pocket is 21 mm, select the 20 mm OD variant. Always confirm the inside diameter clears your guide pin with at least 0.5 mm of radial clearance.

The colours follow ISO 10243: TL-Blue = extra-light load (lowest spring rate), TF-Yellow = light load, TM-Red = medium load, TH-Green = heavy-extra load, TB-Brown = heavy load (highest spring rate). Choose based on the force required at your working deflection. If you are unsure, calculate the required force at 20–30% deflection and match it to the spring rate listed for your chosen size.

Rectangular wire die springs are typically rated for up to 30–40% of free length deflection at maximum load for long fatigue life (typically 1,000,000+ cycles). For shorter run tooling, deflection up to 50% of free length may be acceptable. Operating consistently beyond 40% deflection will shorten service life. Always design your shut height so the spring is not fully compressed (coil-bound) at bottom dead centre.

Yes. The outside diameter, inside diameter, and free length combinations in this listing are designed to match ISO 10243 standard die-spring pocket dimensions. If you are using a non-standard die set, verify the pocket bore, guide pin diameter, and available spring space against the variant dimensions before ordering.

These springs include a corrosion-resistant surface treatment suitable for typical toolroom and moulding environments. For aggressive coolant exposure, consider applying a light coat of grease or anti-corrosion spray during installation. Inspect springs periodically for surface rust, pitting, or set (permanent shortening), and replace any spring that shows visible damage before it causes tooling failure.

It depends on the required force and available pocket space. A single larger-diameter spring can replace multiple smaller springs if the pocket geometry allows. However, using multiple springs in parallel is common when the required force exceeds what a single spring of the available OD can provide, or when load must be distributed evenly across a stripper plate. Calculate total force requirements first, then select the configuration that fits your die layout.

Die springs use rectangular (flat) wire cross-sections, which allows more wire volume per unit length compared to round-wire springs. This results in higher load capacity, greater energy storage, and longer fatigue life within the same outer envelope — making them the standard choice for high-cycle tooling applications like stamping dies and injection moulds where round-wire springs would wear out too quickly.