Green Heavy load Compression Die Spring 6-40mm Diameter & Up To 300mm Long

Measure the pocket bore in your die plate — the spring outer diameter should be 0.5 mm to 1 mm smaller than the bore for a sliding fit. For free length, select a spring whose compressed length at maximum deflection still leaves at least 15% of free length as solid-height clearance. Use the variant selector above to match your OD and free-length requirements.

Per ISO 10243, die springs are color-coded by load class: green indicates Heavy Load — the stiffest category, providing the highest force per unit deflection. Green springs are chosen when maximum stripping or ejection force is needed and space is limited. If you need lighter resistance, consider light (yellow), medium (blue), or extra-heavy (red) rated springs instead.

Chromium-silicon alloy steel offers better corrosion resistance than plain carbon steel, but these springs are not stainless. In environments with continuous coolant exposure or high humidity, applying a light coat of machine oil or grease to the spring surface is recommended. For fully corrosive environments, contact us to confirm suitability or consider stainless alternatives.

Chromium-silicon alloy steel retains its mechanical properties up to approximately 120°C (248°F). Sustained operation above this temperature can cause accelerated stress relaxation and load loss. For high-temperature tooling applications such as hot-stamping dies, a high-temperature alloy spring would be more appropriate.

Yes. Green heavy-load die springs are widely used in injection mold ejector return applications where a firm, consistent return force is required. Select an OD that fits your ejector plate pocket and a free length that provides adequate stroke with sufficient solid-height clearance. Verify the spring's rated load at your required deflection matches your ejector plate weight and friction load.

Choose the load class based on the force your application requires at a given deflection. Green (heavy) springs produce significantly more force per millimeter of compression than blue (medium) or yellow (light) springs of the same size. If your tooling requires maximum stripping force, uses a short stroke, or has limited space for multiple springs, green is the correct choice. If you are unsure, calculate the required stripping or ejection force and compare it to the spring's load-deflection curve for your selected size.

Fatigue life depends on the deflection ratio (actual deflection ÷ maximum rated deflection). Operating at 30% of maximum deflection typically yields over 1,000,000 cycles; at 50% deflection, approximately 500,000 cycles; at 70–80% deflection, life drops significantly. For longest service life, design your tooling so the working deflection stays below 50% of the spring's rated maximum deflection.