JIS Die Springs.

What are JIS Die Springs?

JIS die springs are high-load compression springs manufactured to Japanese Industrial Standards (JIS) tolerances for repeatable force and dimensional consistency.

They are designed for cyclic operation in tooling and machinery where space is constrained, but reliable energy storage and return are essential. In press tools and injection moulding, they provide reliable push-back and steady performance, helping machines run smoothly and avoid unexpected stops.

How JIS Die Springs Work

Under load, a JIS die spring compresses to store energy and returns to its original length when released, delivering a consistent, repeatable force.

Tight JIS tolerances keep the outer diameter and free length uniform from batch to batch, so springs fit standard pockets and maintenance stays straightforward. 

Strength classes, from extra light to extra heavy, let you match spring rate and safe working travel to the application: lighter classes suit longer strokes and delicate parts; heavier classes handle higher forces over shorter strokes.

Materials JIS Die Springs Are Made From

Our selection of JIS die springs is manufactured from steel, chosen for its high compressive strength and fatigue resistance under repeated cycling, supporting stable performance and dimensional integrity in demanding tooling environments.

Sizes and Types of JIS Die Springs Available

Accu’s range of JIS die springs is available in the sizes and strength classes below, helping you match your pocket size and required force.

• Outer Diameter (OD): 8 mm to 70 mm
• Free Length: 10mm to 350mm
• Strength Classification: Extra Light, Light, Medium, Heavy, Extra Heavy

These options enable straightforward selection to suit available pocket sizes and target forces across a wide range of tooling layouts.

FAQs

What distinguishes JIS die springs from general compression springs?

JIS die springs are built to JIS manufacturing tolerances for OD and free length, enabling consistent fit in standardised spring pockets and predictable force–deflection behaviour across production batches.

How do I choose between Extra Light, Light, Medium, Heavy, and Extra Heavy?

Match the class to your required force and stroke. Lighter classes support longer deflection at lower force and heavier classes provide higher force over shorter working strokes.

Start with your available space (OD and free length), define the working deflection, then select the class that delivers the target force within recommended operating limits.

Are JIS die springs suitable for high-cycle applications in presses and moulds?

Yes, provided the spring is operated within its recommended working deflection for the chosen strength class and installed squarely in a correctly sized pocket to minimise side-loading.

How should I measure to replace an existing die spring?

Measure the outer diameter and free length with the spring removed and unloaded. Note the strength classification (often identified by colour or part code), then match these parameters to the replacement.

What do the spring colours mean?

Colour markings identify the strength classification (e.g., Extra Light through Extra Heavy). This helps maintenance teams quickly verify specifications during changeovers. For exact colour matching, please refer to our colour chart guide for die springs.

Bespoke JIS Die Springs Manufacture.

High precision, bespoke manufacture of JIS Die Springs to customer specification. State of the art facilities specialising in both small batch prototyping and large scale manufacture.