Heavy Load Duty Compression Die Spring Brown 8mm-35mm Outer Dia 20mm-300mm Long

Match the outer diameter (OD) to your die spring pocket bore, and the inner diameter (ID) to your guide pin diameter — the ID should be slightly larger than the pin for clearance. Then select a free length that gives you the required working stroke at your target deflection percentage (typically 20–30% of free length for heavy-load springs). Refer to your tooling drawings for pocket depth and stroke requirements.

Brown indicates the Heavy Load rating per ISO 10243, the international standard for die springs. The color system classifies springs by load category: light (yellow), medium (blue), heavy (red), and extra-heavy (brown). Brown springs deliver the highest force-per-unit-deflection in the standard die spring series, making them suitable for applications requiring maximum return force in a compact envelope.

Yes. These heavy-load die springs are commonly used in injection mold ejector plate return systems. Select an OD that fits your spring pocket and an ID that clears your ejector guide pin. Ensure the free length and deflection range match your mold's ejector stroke. For high-cycle molds, the shot-peened surface treatment helps extend service life.

These springs are made from chromium alloy steel, which offers improved corrosion resistance compared to plain carbon steel. However, they are not stainless steel and are not intended for continuous exposure to water, acids, or highly humid environments without additional protection. For corrosive environments, consider applying a light machine oil coating or consult us about alternative material options.

For heavy-load (brown) die springs, the recommended maximum working deflection is typically 20–30% of the free length for extended fatigue life. Operating beyond 30% deflection significantly reduces cycle life. For example, a 100mm free-length spring should ideally be deflected no more than 20–30mm per stroke in continuous-cycle applications.

Yes, these are specifically designed for stamping and blanking die applications. They provide the high return force needed to strip material from punches and return stripper plates reliably. Select the OD and free length based on your die pocket dimensions and required stripping force. Multiple springs are often used in parallel to achieve the total force required.

The outer diameter is determined by your die spring pocket size. Larger OD springs carry more load capacity for a given free length. If you need more force but are constrained by pocket size, consider using multiple smaller springs in parallel rather than exceeding the rated deflection of a single spring. Always verify the ID clears your guide pin with at least 0.5–1mm of radial clearance.