Quick answer
A disc spring does not have one fixed load value. The load depends on how far the Belleville washer or DIN 2093 disc spring is compressed. On a load-deflection curve, the horizontal axis is usually deflection s and the vertical axis is load F.
For selection, first calculate the deflection from free height and working height. Then read the load at that working point. This is more useful than asking for maximum load, especially when the spring works in a valve, flange joint, actuator or compact preload assembly.
How F and s are used
F is the spring load. s is the deflection or compression amount. If a disc spring has a free height of 6.0 mm and is installed at a working height of 4.8 mm, the deflection is 1.2 mm.
The next engineering question is: what load does this spring produce at 1.2 mm deflection? If the deflection is too small, preload may be weak. If the spring is compressed too far, stress, fatigue life, relaxation and assembly tolerance need closer review.
- Free height and working height define the real deflection.
- The working point is the load point that matters in the assembly.
- Near-flat operation should be reviewed carefully in cyclic or hot service.
Where a calculator helps
A calculator is useful for early screening because it connects geometry, material, temperature and stack arrangement with an estimated load direction. It is not a final guarantee for critical equipment.
For high temperature, corrosive media, frequent cycling or safety-related assemblies, the calculation should be followed by drawing review, material review and application checks.
Frequently Asked Questions
How do you read a disc spring load-deflection curve?
Start with deflection s on the horizontal axis, then read the corresponding load F on the vertical axis. The important value is the actual working point after installation.
Can load be determined from OD, ID and thickness only?
Only roughly. Free height, working height, material, temperature, friction, stacking and guidance also affect the real load.
How does stacking affect the curve?
Parallel stacking increases load. Series stacking increases travel. Combined stacking adjusts both, but friction and guidance must still be reviewed.
Need FeTech to review your disc spring application?
Send the drawing, stack envelope, load target, temperature, media and quantity. Our team can check material direction, stack logic and quotation readiness.
- DIN 2093 replacement or custom geometry
- Valve, flange, actuator and severe-service stacks
- Material review for stainless, Inconel, Hastelloy, titanium or heat-resistant steel
Final geometry, fatigue life, K4 source, friction and support-face conditions still require engineering confirmation.