Belleville Washers & Conical Disc Springs Immense axial load in a compact installation space
Optimise your critical applications with world-class conical disc springs from Reliable Pressings. Engineered to supply immense axial load capacity within exceptionally compact installation spaces, our conical springs offer predictable, uniform performance under the most strenuous industrial conditions.
At last count we had manufactured more than 700 different “coned annular-disk springs of uniform cross section (radially symmetric) proportioned to provide a wide variety of load-deflection curves”, each with a unique set of dimensions, and generally with surprisingly consistent, repeatable and reliable performance.
These range from small ODs of a few millimetres, weighing less than a gram, to springs that are more than 20 mm thick, over 500 mm in outer diameter, weigh kilograms each and are designed to take loads of many tonnes.
The Basics First
We have provided as much information on our website as we thought necessary, and with the FAQ we expect you’ll find some useful answers. If you need to talk, feel free to call us. We are here to help.
Belleville Load Washers vs Conical Disc Springs
The two products that most often get confused.
There are two broad categories of conical spring (also called Belleville, bevel or cup washers). Firstly, there are the DIN 6796 heavy load washers. They are used to secure static bolted connections with high load demands. The disc spring design ensures a permanent force on the joint between the bolt and its nut, and so prevents the loss of preload. Unsurprisingly, these come in sizes that correspond to bolt sizes. We cater for the smallest (M2) to the largest bolt size (M125). We carry a range of the popular sizes (commercial standards) in stock and manufacture the remainder (bespoke) on demand. The sizes are given on the page linked above.
Then there are the DIN EN 16983 (formerly DIN 2093) conical disc springs. These are specifically designed to work as springs, and a load characteristic curve shows the expected relationship between the force applied and the resulting travel (compression) of the spring.
The first graph below is the load characteristic curve for a Group 2, 18.4 × 50 × 2 disc spring with an overall height of 3.65 mm. The second is that of a Group 3, 64 × 125 × 7 reduced-thickness disc spring (that is, with contact flats), where t′ = 6.55 mm and l0 = 10 mm.
Characteristic Load Curve Verification
As part of our services and quality assurance, we will calculate the expected load characteristic curve of any disc spring stack a customer is considering. The behaviour of a single disc spring is given in our standard product data sheet, and we always ask for the stack configuration, preload and final load settings of your application. From this data we calculate the expected result, which we warrant.
We regularly conduct witnessed load testing by an independent third party, most commonly SGS Metlab or the CSIR’s mechanical testing labs. With your order you can receive:
- a mill/material certificate and confirmation of the element composition of the alloy used;
- a hardness test to confirm that the disc springs have been correctly quenched and tempered and the correct hardness achieved;
- load characteristic curves showing the expected load and compression, relating force to travel.
Serving Mission-Critical Industries
Our precision-engineered conical washers are trusted across demanding industries worldwide.
Aerospace & Defence
Lightweight, ultra-reliable components that endure extreme G-forces, flight vibration and cyclic temperatures.
Mining & Heavy Equipment
Impact-resistant disc springs that tolerate immense shocks, continuous vibration and abrasive underground conditions.
Agricultural Machinery
Durable heavy-clamping solutions built to withstand harsh outdoor weather and relentless mechanical cycling.
Oil, Gas & Processing
Reliable valve actuation and sealing preloads, including high-temperature INCONEL, to prevent catastrophic leaks.
Machining
From CNC tool holders and spindles to arc-furnace electrode holders.
What they do
Safety-critical tensioning, energy storage and compensation for thermal expansion.
There they perform a wide variety of functions:
- Bolted joints & connections: preventing loosening due to vibration or thermal expansion.
- Valves & actuators: ensuring reliable sealing pressure in oil and gas systems.
- Brake systems: providing consistent force in heavy machinery and automotive braking.
- Electrical switchgear: maintaining busbar joint tension under cyclic thermal loading.
- Bearing preload: doubling the life of bearings in demanding operating environments.
Where to Next?
FAQ
Quick answers to the questions we are asked most.
Read the FAQ →DIN 6796 load washers
Everything you need, including bolt sizes and dimensions, on its dedicated page.
Load washers →DIN EN 16983 disc springs
Groups, series, stacking and the key points on disc springs.
Conical disc springs →Design calculations
Our approach to design calculations and load characteristic verification.
Design approach →Ordering
The information we need to make sure you get exactly what your application requires.
Ordering & quotes →Available sizes
Search and filter all our standard disc spring sizes online.
Find a size →Although we are best known for the larger Group 3 reduced-thickness disc springs with contact flats (thicknesses over 6 mm), we cater for the smaller sizes too. Download the lists of all the Group 1 and 2 sizes and all the Group 3 disc springs we offer as standard.
If you need to read up on spring steel and the various alloys available, as well as the key points of heat treatment, visit our sister company’s website, Cheng Xin Spring Steel. It has short introductions to key terms: yield strength, stress–strain curves, plasticity and deformation, hardening vs hardenability, and the naming conventions for steel. If you are curious, read these introductory topics.
Need a disc spring or a whole stack?
Tell us your application, loads and installation space. We’ll design, verify and manufacture it.