Die Springs — ISO 10243 Color-Coded
Rectangular wire chrome silicon die springs standardized per ISO 10243 / JIS B 5012. Five load classes from extra light (green) to extra heavy duty (yellow). JIS metric and Inch standards from MISUMI, DANLY IEM, Lamina, and LEMPCO.
Products in This Category
JIS Standard Medium Duty Die Spring - 50% Deflection, Chrome Silicon | Reliable Medium Load Support | MISUMI
JIS Standard Chrome Silicon Medium Duty Die Spring provides 50% deflection for stable medium load support. Oil-tempered wire for reliable performance.
JIS Standard Chrome Silicon Steel Medium Duty Die Spring - 40% Deflection | SWOSC-V Equivalent Wire | MISUMI
Medium Duty Die Spring - 40% Deflection uses chrome silicon steel (SWOSC-V equivalent) oil-tempered wire for stable spring force in dies. Request a quote.
JIS Standard Medium Duty Die Spring 32% Deflection | Chrome Silicon | Coil Spring Performance | MISUMI
JIS Standard Medium Duty Die Spring 32% Deflection in Chrome Silicon steel wire for reliable coil spring return. Designed for medium load applications—request a quote.
JIS Standard Heavy Duty Die Spring 20% Deflection Chrome Silicon Oil-Tempered Wire | MISUMI | MISUMI
Heavy Duty Die Spring 20% Deflection, built from Chrome Silicon oil-tempered wire to support stable die performance. Request a quote for supply.
DieMax XL™ Light Duty Die Spring 40% Deflection Chrome Silicon (Inch) | DANLY IEM | DANLY IEM
DieMax XL™ Light Duty Die Spring 40% Deflection Chrome Silicon (Inch) for light loads. Consistent force helps absorb vibration; request a quote.
JIS Standard Heavy Duty Die Spring 24% Deflection Chrome Silicon | Robust Support | Fast Fulfillment | MISUMI
Heavy Duty Die Spring 24% Deflection (Chrome Silicon) for heavy load die return. Built to deliver resilient support under stress. Request a quote.
Heavy Duty Die Spring Chrome Silicon - 30% Deflection (DieMax XL™) | DANLY IEM | DANLY IEM
Heavy Duty Die Spring Chrome Silicon (DieMax XL™) with 30% deflection for inch applications. Reliable under heavy loads—built for long service life. Request a quote.
JIS Standard Chrome Silicon Medium Duty Die Spring 60% Deflection | Durable Coil Spring | MISUMI
JIS Standard Chrome Silicon Medium Duty Die Spring 60% Deflection for medium load applications. Oil-tempered coil spring supports controlled springback—request a quote.
DieMax XL™ Medium Duty Die Spring - 37.5% Deflection, Chrome Silicon, Inch | DANLY IEM | DANLY IEM
Medium Duty Die Spring 37.5% Deflection (Chrome Silicon) for inch applications with consistent load characteristics and vibration damping. DANLY IEM reliability—request a quote.
Extra Heavy Duty Die Spring Inch, 25% Deflection, Chrome Silicon | DANLY IEM DieMax XL™ | DANLY IEM
Extra Heavy Duty Die Spring Inch with 25% deflection in Chrome Silicon for dependable shock absorption and stable load capacity in die and press systems. Request a quote.
JIS Standard Extra Heavy Duty Die Spring SWG Type - 20% Deflection | Reliable Support | Fast Delivery | MISUMI
JIS Standard Extra Heavy Duty Die Spring SWG Type with 20% deflection delivers reliable load support for heavy die applications. Request a quote.
JIS Standard Extra Light Duty Die Spring - 50% Deflection, Chrome Silicon | DANLY IEM Advantage | DANLY IEM
JIS Standard Extra Light Duty Die Spring - 50% Deflection provides stable load support with chrome silicon steel. Request a quote.
JIS Standard Light Duty Die Spring 40% Deflection | DANLY IEM Advantage | DANLY IEM
JIS Standard Light Duty Die Spring 40% Deflection by DANLY IEM. Chrome silicon design for stable light-load performance—request a quote.
Inch Medium Duty Die Spring - 40% Deflection, Chrome Silicon | Lamina Load-Balanced Performance | Lamina
Inch Medium Duty Die Spring - 40% Deflection, Chrome Silicon by Lamina. Chrome silicon steel for durable medium-duty load support. Contact us for pricing.
Medium Heavy Duty Die Spring 35% Deflection Chrome Silicon | Inch | LEMPCO | LEMPCO
Medium Heavy Duty Die Spring 35% Deflection with chromium silicon alloy for reliable springback in die work. Inch sizes, contact LEMPCO for quote.
Extra Heavy Duty Die Spring 25% Deflection Chrome Silicon | Inch | Fast Delivery | LEMPCO
Extra Heavy Duty Die Spring 25% Deflection for die applications (Chrome Silicon). Designed for reliable load performance in inch systems—request a quote.
JIS Standard Chrome Silicon Medium Duty Die Spring - 32% Deflection | DANLY-IEM | DANLY IEM
JIS Standard Chrome Silicon Medium Duty Die Spring - 32% Deflection for reliable die return under controlled load. DANLY-IEM coil springs for consistent forming.
JIS Standard Medium Load Round Wire Die Spring - 37.5% Deflection | DANLY IEM Advantage | DANLY IEM
Round wire die spring for medium load applications with a 37.5% allowable deflection ratio. Blue-inch DieMax XL™ spring by DANLY IEM—request a quote.
JIS Standard Extra Heavy Duty Die Spring SWV 13% Deflection | Chrome Silicon | Fast Delivery | MISUMI
JIS Standard SWV Extra Heavy Duty Die Spring with 13% deflection supports heavy loads and dampens shock in die work. Chrome silicon construction. Request a quote
Inch Standard Medium Duty Die Spring 40% Deflection | Chrome Silicon | LEMPCO Advantage | LEMPCO
Medium Duty Die Spring 40% deflection for inch tooling, made from chrome silicon alloy. Built for stable die life and controlled deflection. Request a quote.
JIS Standard SWX Type High Speed Die Spring - 10% Deflection, Chrome Silicon | Fast Delivery | MISUMI
JIS Standard SWX Type high speed die spring with 10% deflection ratio for stable support in die work. Chrome silicon steel for repeatable performance. Request a quote.
JIS Standard Chrome Silicon Heavy Duty Die Spring 24% Deflection | DANLY-IEM | DANLY IEM
Heavy Duty Die Spring 24% Deflection for die cushioning. Chrome silicon design with JIS standard build helps heavy-load forming. Request a quote.
Medium Heavy Duty Die Spring 35% Deflection Chrome Silicon | Inch | Lamina | Lamina
Medium Heavy Duty Die Spring 35% Deflection Chrome Silicon for inch systems. Engineered inch-format coil strength for reliable die cushioning. Contact us.
Heavy Duty Die Spring 28% Deflection, Chrome Silicon, Inch | Lamina Supply | Lamina
Heavy Duty Die Spring 28% Deflection with Chrome silicon construction for demanding die applications, designed for stable long-cycle performance. Request a quote.
Inch Round Wire Die Spring - 30% Deflection | DieMax XL™ Advantage | DANLY IEM
Inch Round Wire Die Spring with 30% allowable deflection for consistent heavy-load performance. DieMax XL™ style wire spring for die applications—request a quote.
Light Load Round Wire Die Spring - 40% Deflection | DANLY IEM | Made for Inch Dies | DANLY IEM
Light Load Round Wire Die Spring for inch die assemblies with a 40% allowable deflection ratio. Chrome-silicon construction for stable die return.
Chrome Silicon Inch Extra Heavy Duty Die Spring - 20% Deflection | Lamina | Lamina
Extra Heavy Duty Die Spring - 20% deflection in chrome silicon steel for durable die return under load. Inch standard design for dependable performance. Request a quote.
JIS Standard Heavy Duty Die Spring - 13% Deflection | Chrome Silicon | Fast Delivery | MISUMI
JIS Standard Heavy Duty Die Spring - 13% Deflection (Chrome Silicon) supports heavy loads up to 16,045 N for reliable tooling performance. Request a quote.
Heavy Duty Die Spring 28% Deflection Chrome Silicon | LEMPCO | LEMPCO
Heavy Duty Die Spring 28% Deflection Chrome Silicon for die and tooling applications. Built from high-strength chromium silicon alloy for durability—request a quote.
JIS Standard Extra Heavy Duty Die Spring - 20% Deflection | Chrome Silicon | DANLY-IEM | DANLY IEM
Extra Heavy Duty Die Spring - 20% Deflection (chrome silicon) in JIS configuration. Supports heavy die loads with reliable shock absorption. Contact us.
Die Spring Load Classes & Color Code System
ISO 10243 standardizes die spring selection using a universal color code system. Each color maps directly to a maximum safe deflection rate and load capacity range.
Step 1: Select Load Class by Color Code
| Color Code | 🟢 Green | 🔵 Blue | 🔴 Red | 🟡 Yellow | ⬛ Brown/Black |
|---|---|---|---|---|---|
| Load Class | Light Duty | Medium Duty | Heavy Duty | Extra Heavy Duty | High Speed |
| Max Deflection | 40–50% | 32–40% | 20–28% | 13–25% | 10% |
| Relative Load | Lowest | Medium | High | Highest | Extreme (short stroke) |
| Fatigue Life at Rated | Longest | Long | Medium | Shorter | Shortest per cycle |
| Typical Application | Light stripping, guide returns | Standard stripping, moderate blanking | Heavy blanking, deep draw holding | Maximum force blanking | High-speed progressive dies |
| Available Standards | JIS / Inch | JIS / Inch | JIS / Inch | JIS / Inch | JIS only |
| Brands | MISUMI, DANLY, Lamina, LEMPCO | MISUMI, DANLY, Lamina, LEMPCO | MISUMI, DANLY, Lamina, LEMPCO | MISUMI, DANLY, Lamina, LEMPCO | MISUMI |
Step 2: Understand the Engineering Behind the Color Code
Chrome Silicon Alloy Wire (SWOSC-V)
All die springs use chrome silicon alloy wire (SWOSC-V or equivalent), heat-treated to HRC 48-52. This alloy provides the optimal combination of high tensile strength (1,900-2,100 MPa) and fatigue resistance required for millions of compression cycles. The rectangular wire cross-section is the key differentiator from round wire springs — it maximizes the material's load-bearing capacity within a given outer diameter envelope, delivering 30-50% more force than a round wire spring of the same size.
Color = Deflection Limit = Fatigue Life
The color code is not arbitrary — it directly maps to the spring's maximum safe deflection ratio. Exceeding the rated deflection by 5% reduces fatigue life by approximately 10×. This is because stress in the wire increases exponentially near the deflection limit, accelerating fatigue crack initiation at the wire surface. The ISO 10243 safety rule: always select one color class above the calculated minimum — this provides the recommended 20% safety margin.
JIS vs Inch: Dimensional Standards
JIS (Japanese Industrial Standard) and Inch (NAAMS/North American) springs use different dimensional series but identical material and heat treatment. JIS springs use metric hole sizes (Ø10, Ø12, Ø14...) while Inch springs use imperial bore sizes (3/8 inch, 1/2 inch, 5/8 inch...). Load class color coding is universal across both standards — a 'red' spring from MISUMI JIS and a 'red' spring from Lamina Inch have equivalent load characteristics relative to their respective bore sizes.
Reference: For a complete color code chart with numeric load values per size, see our What Do Die Spring Color Codes Mean — ISO 10243 Load Class Guide. For brand-specific comparisons, see How to Compare Die Spring Brands — MISUMI vs Lamina vs DANLY vs LEMPCO.
About Die Springs
Die springs are the workhorse of press die tooling — rectangular wire chrome silicon springs engineered for high-load, high-cycle stamping applications. Our 30-product range covers the complete ISO 10243 color spectrum from extra light (green, 50% deflection) through extra heavy duty (yellow, 13% deflection), plus specialized high-speed springs for progressive die applications. Available in both JIS metric and Inch dimensional standards from four major brands: MISUMI, DANLY IEM (including DieMax XL™), Lamina, and LEMPCO.
Application Scenarios
High-Volume Progressive Dies
Multi-station progressive dies running 1M+ cycles/year need springs that maintain consistent force across all stations.
Why die springs fit: ISO 10243 color coding ensures identical force characteristics across every station. Chrome silicon fatigue life exceeds 1M cycles at 80% rated deflection.
High-Speed Stamping (>200 SPM)
High-speed presses exceeding 200 strokes per minute generate dynamic loads that exceed standard die spring ratings.
Why specialized die springs fit: High Speed class (10% deflection, Brown/Black) is engineered specifically for minimal stroke with maximum return speed, preventing spring resonance at high SPM.
Frequently Asked Questions
Engineering Resources
What Do Die Spring Color Codes Mean — ISO 10243 Load Class Guide
Complete ISO 10243 color code reference with load values per bore size and deflection limits.
How to Compare Die Spring Brands — MISUMI vs Lamina vs DANLY vs LEMPCO
Four-brand comparison covering specification coverage, dimensional standards, and delivery performance.
Frequently Asked Questions
How do die spring color codes (green, blue, red, yellow) map to load capacity?+
What is the maximum safe deflection for each die spring load class?+
What is the difference between JIS metric and Inch die spring standards?+
How do MISUMI, Lamina, LEMPCO, and DANLY die springs compare in quality and availability?+
What is the expected fatigue life of a chrome silicon die spring at rated deflection?+
Engineering Resources
What Do Die Spring Color Codes Mean — ISO 10243 Load Class Guide
Complete ISO 10243 color code reference with load values per bore size and deflection limits.
How to Compare Die Spring Brands — MISUMI vs Lamina vs DANLY vs LEMPCO
Four-brand comparison covering specification coverage, dimensional standards, and delivery performance.
Need a Custom Quote?
Specify your die spring color class, outer diameter, bore diameter, free length, and quantity. We stock all ISO 10243 color classes in JIS metric and Inch standards from MISUMI, DANLY, Lamina, and LEMPCO.