Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.
When a standard spring fails under repeated load cycles, engineers and makers reach for a die spring. If you work with hydraulic presses, stamping tools, injection molds, or industrial jigs, you know the frustration of a spring that creeps, fatigues, or loses rate after a few thousand cycles. These Ø12mm heavy-load compression die springs are built for exactly those demanding applications — available in five color-coded load grades and a wide range of lengths so you can match the spring to your exact force requirement.
Each spring features an outer diameter (OD) of 12 mm (~0.47 in) and an inner diameter (ID) of 6 mm (~0.24 in), with free lengths ranging from 20 mm (~0.79 in) up to 100 mm (~3.94 in). The color coding — Yellow, Blue, Red, Green, and Brown — follows the ISO 10243 die spring standard, indicating progressively heavier load ratings from light to extra-heavy duty. Springs are available individually (1 pc), in pairs (2 pcs), or in packs of five (5 pcs).
Typical use cases include compression die spring replacement in punch-and-die tooling, guide pin return springs in progressive stamping dies, spring-loaded clamps and fixtures for CNC machining setups, and custom actuator return mechanisms in automation and robotics projects. The standardized OD/ID dimensions make these a direct drop-in for ISO 10243-compliant spring pockets.
| Outer Diameter (OD) | 12 mm (approx. 0.47 in) |
|---|---|
| Inner Diameter (ID) | 6 mm (approx. 0.24 in) |
| Free Length Range | 20 mm – 100 mm (0.79 in – 3.94 in) |
| Wire Cross-Section | Rectangular (die spring profile) |
| Material | Spring steel (high-carbon, rectangular wire) |
| Load Grade / Color | Yellow / Blue / Red / Green / Brown (ISO 10243 color coding) |
| Standard Reference | ISO 10243 die spring series |
| Spring Rate | See variant options |
| Maximum Deflection | See variant options |
| End Type | Closed and ground ends (typical for die springs) |
| Surface Finish | See variant options |
| Packing Quantity | 1 pc / 2 pcs / 5 pcs (select above) |
ISO 10243 die springs use color to indicate load class: Yellow = light load, Blue = medium load, Red = heavy load, Green = extra-heavy load, and Brown = ultra-heavy load. Start by calculating the force required at your working deflection, then select the color whose rated load at that deflection meets or slightly exceeds your requirement. If you are replacing an existing spring, match the color and dimensions of the original.
The free length should be long enough so that the spring is still under some preload when installed (typically 5–10% deflection at assembly), and the compressed length at maximum stroke must not exceed the solid height of the spring. As a general rule, select a free length that gives you the required working stroke with a safety margin of at least 15% before solid height. Measure your spring pocket depth and maximum stroke, then choose accordingly from the 20–100 mm range available.
Yes. With an OD of 12 mm and an ID of 6 mm, these springs are dimensioned to the ISO 10243 standard for Ø12 mm die springs. They will fit spring pockets bored to the standard clearance diameter and slide over guide pins turned to the standard pin diameter. Always verify the pocket bore and pin diameter in your tooling drawings before installation.
Load capacity depends on the color (load grade) and the free length selected. Shorter springs of the same color produce higher force per unit deflection (higher spring rate), while longer springs of the same color produce lower force per unit deflection. For exact load and rate values, refer to the ISO 10243 load tables for Ø12 mm springs at your chosen color grade, or contact us to confirm the specification for your specific variant.
Die springs wound from rectangular-section spring steel are designed for high-cycle fatigue life. When operated within the recommended deflection range (typically up to 30–40% of free length for heavy-load grades), service life of hundreds of thousands to over one million cycles is typical. Exceeding the maximum recommended deflection significantly reduces fatigue life. Replace springs showing visible set (permanent shortening), cracking, or corrosion.
These springs are made from high-carbon spring steel, which provides excellent mechanical properties but has limited inherent corrosion resistance. For wet, humid, or outdoor environments, apply a light coating of machine oil or grease, or consider using them in a protected housing. For highly corrosive environments, contact us to discuss alternative material options.
Absolutely. While die springs are most commonly used in stamping and injection mold tooling, their compact envelope, high load capacity, and consistent spring rate make them well-suited for spring-loaded clamps, fixture return mechanisms, valve actuators, robotics joints, and custom machinery wherever a reliable, high-force compression spring is needed in a 12 mm OD package.
Order 1 pc if you need a single replacement or are prototyping. Order 2 pcs if your tooling uses springs in pairs (common in symmetric die sets). Order 5 pcs for multi-cavity molds, to have spares on hand for production tooling, or to reduce per-unit cost. The 5-pack offers the best value per spring for ongoing production use.
