Customer-ready PDF worksheets
Use these practical English PDFs before quotation or forward them directly to a customer who needs to organize application data.
These PDFs are RFQ preparation resources. Final material, geometry, stack, fatigue and installation decisions still require FeTech engineering review.
Why stack design matters
A search for disc spring stack usually means the buyer already has a mismatch: the load is too high for one washer, the movement is too large, or the available height is too tight. One disc spring may be close, but not close enough for the assembly.
Stack design lets FeTech tune the spring pack while keeping a proven geometry family whenever possible.
What parallel stacks do
In a parallel arrangement, disc springs are nested in the same direction. The stack carries more force, but the available working deflection stays close to one spring.
Parallel packs are used when the assembly needs more clamp load but the diameter and movement window are already limited.
What series stacks do
In a series arrangement, disc springs alternate direction so the stack gains more total travel. The load level stays closer to that of one spring, but the system can accommodate more movement before reaching its working limit.
This is why series stacking is common in live loading, settlement compensation and other applications where the joint keeps moving after installation.
Where combined stacks are used
Many real projects are not a clean force-or-travel choice. By grouping several springs in parallel and then placing those packets in series, the design can raise clamp load while keeping usable movement in reserve.
That is the logic behind many valve stacks, industrial bolting packs and custom elastic assemblies.
- Parallel for more force.
- Series for more travel.
- Combined stacks when the joint needs both.
- Final design should still be checked against working deflection, fatigue target and installation tolerance.
When to use the calculator before requesting a quote
For early sizing, a calculator can show whether the stack should move toward force, travel or a combined arrangement. It will not replace engineering review, but it prevents the first RFQ from being only a guess.
The best inputs are outside diameter, inside diameter, thickness, free height, target load, available movement and the application type: valve, flange, actuator or custom preload assembly.
Frequently Asked Questions
Does a larger stack always mean better performance?
No. A larger stack may add force or travel, but it can also create height, alignment, friction or load-distribution problems if it is not matched to the joint.
What information is needed to review a stack design?
The most useful inputs are required load, available deflection, installation height, duty cycle, operating temperature and whether the stack is used statically or dynamically.
How does series vs parallel stacking change load and travel?
Parallel stacking increases load while keeping travel close to a single spring. Series stacking increases travel while keeping load close to a single spring. Mixed stacks combine both effects but need guidance and friction review.
What is the main risk in a mixed disc spring stack?
The main risks are uneven load sharing, excessive friction, wrong orientation, insufficient guide clearance and stack height variation. These can change the real load curve from the calculated value.
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.