High force
The thickest spring for a given external diameter. Short travel. Ideal when axial space is tight and the required force is high — clutches, safety valves, heavy preload.
Disc springs
DIN 2093 / DIN EN 16983
Permanent stock
300+ standard references
Mainland delivery
24 h · direct from stock
External diameter
8 — 250 mm (standard)
01
What are disc springs?
Conical washers with elastic properties, known as disc springs, disc washers or Belleville springs. The DIN 2093 / DIN EN 16983 standard sets out all the dimensional, mechanical and heat-treatment characteristics these parts must meet.
Their main advantage over traditional helical springs is the ability to generate very high elastic forces in comparatively small housings and with small deflections.
By stacking them in series or in parallel, you can tune both the force and the total travel of the assembly to the exact value the application requires. Their elastic properties allow them to work in both dynamic applications (repeated load and unload cycles) and static ones (permanent preload).
02
Series A, B and C per DIN 2093 / DIN EN 16983
The DIN 2093 / DIN EN 16983 standard classifies standard disc springs into three series according to the ratio between the external diameter (De) and the material thickness (t). For each external diameter defined by the standard there are three versions with a different force level — usually referred to by the series letter and the external diameter (for example: A-50 or B-71).
NOTE
In addition to the three standard series, it is possible to manufacture disc springs with intermediate thicknesses that, while still meeting the standard, do not correspond to any of the three tabulated series.
03
Contact surfaces · t vs. t′
The DIN 2093 / DIN EN 16983 standard recommends that discs with a thickness greater than 6 mm be manufactured with contact surfaces. These surfaces increase the contact area between the springs, improving stress distribution and reducing wear.
In disc springs with contact surfaces, a distinction must be made between the theoretical material thickness (t) and the reduced thickness (t′), which is the actual thickness in the contact area. The difference between t and t′ is relevant when designing a parallel stack, as it directly affects the total height of the assembly.
In the catalogue
In the Surisa catalogue you can find the same disc spring with and without contact surfaces; in many cases both versions are interchangeable, but depending on the application one may be more suitable than the other.
FIG · comparative section
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04
Definitions and technical parameters
The following parameters appear on drawings, calculation sheets and catalogue tables. Getting familiar with the nomenclature is essential to order a reference correctly or to validate a stack.
| Parameter | Meaning |
|---|---|
| De | External diameter of the spring |
| Di | Internal diameter of the spring |
| t | Theoretical material thickness |
| t′ | Reduced thickness — only in disc springs with contact surfaces |
| ho | Maximum deflection · free travel |
| lo | Total free height · lo = t + ho (without contact surfaces) · lo = t′ + ho (with contact surfaces) |
| F(0,75 ho) | Force in N at 75% of maximum deflection — recommended dynamic working load |
Total height formula: lo = t + ho (without contact surfaces) — lo = t′ + ho (with contact surfaces)
FIG · technical dimensions
— Catalogue specifications
- Reference standard DIN 2093 · DIN EN 16983 (replaces DIN 2093 since 2017).
- Standard series A (De/t ≈ 18) · B (De/t ≈ 28) · C (De/t ≈ 40). High, medium and low force.
- External Ø range (De) 8 – 250 mm in the standard catalogue. Custom manufacturing up to 1,000 mm.
- Material thickness (t) 0.2 – 14 mm. Contact surfaces recommended from t > 6 mm.
05
Stacking in series and in parallel
Disc springs can be combined into stacks to obtain custom force and travel characteristics. The choice between series, parallel or a combined configuration is one of the most important design decisions in a disc spring system.
Same orientation
The springs are stacked directly. The total travel equals that of a single piece; the force increases in proportion to the number of units. The force loss due to friction between pieces must be taken into account.
Alternating
The springs are placed alternating the orientation. The resulting force equals that of a single piece; the total travel is multiplied in direct proportion to the number of units.
Combination
It is possible to combine series and parallel, and even to mix disc springs of different thickness. This produces an F/s curve with progressively stiffer stages: the thinner ones flatten first, progressively increasing the force needed for further travel.
FIG · stacking configurations
FIG · real applications
— Practical rules for sizing
- Recommended minimum preload
- ≥ 15% of total travel
- Recommended maximum dynamic load
- ≤ 75% of total travel — F(0.75 ho)
- Initial relaxation loss
- ~ 5% during the first two weeks after assembly
- Mixing thicknesses
- Allowed in series — produces an F/s curve with progressively stiffer stages
06
Guiding and lubrication of the stack
The correct operation of a disc spring stack depends largely on its assembly. The hysteresis caused by friction between pieces and between these and the guiding elements can shift the actual load-deflection curve away from the theoretical one.
— Guiding
The most common method is by internal diameter on a shaft. Outer guiding by means of a sleeve is also possible. In both cases the tolerances of the DIN 2093 / DIN EN 16983 standard must be observed.
The guiding surfaces in contact with the pieces must be polished and hardened to a minimum of 55 HRC over a depth of 0.80 mm. In long stacks, spacer discs may be needed to prevent buckling.
— Lubrication
It is essential both between the pieces and between these and the guide. Depending on the working environment, oils, greases, molybdenum disulphide (MoS₂) pastes or other specific lubricants can be used. For applications where friction is critical, there are special guiding solutions with rings or balls between the pieces that replace sliding contact with rolling contact.
— Guiding tolerances · DIN 2093
| Diameter · Di or De (mm) | Tolerance (mm) |
|---|---|
| Up to 16 | 0.2 |
| > 16 to 20 | 0.3 |
| > 20 to 26 | 0.4 |
| > 26 to 31.5 | 0.5 |
| > 31.5 to 50 | 0.6 |
| > 50 to 80 | 0.8 |
| > 80 to 140 | 1.0 |
| > 140 to 250 | 1.6 |
07
Fatigue and relaxation of disc springs
When they flex, disc springs withstand stresses that are higher at certain points of their geometry. The level of these stresses and the number of working cycles determine the service life of the stack.
— Fatigue
Predicting cycles from travel
It cannot be predicted exactly, but knowing the initial and final travel of the dynamic stroke makes it possible to estimate the expected number of cycles. This calculation is especially useful for comparing alternative stacking configurations.
Heat treatment
- Austenitizing Better elastic qualities
- Hardened + shot peening Excellent fatigue resistance
— Relaxation
Pre-setting mandatory by standard
Any disc spring subjected to a constant compression load over a prolonged period will experience a gradual loss of force. To minimise it, all springs manufactured to DIN 2093 / DIN EN 16983 undergo a pre-setting process: they are fully flattened and any that do not recover their initial height are discarded.
~5%Estimated force loss during the first two weeks after assembly. From then on the stack stabilises.
08
Materials, treatments and finishes
Surisa disc springs are manufactured in a wide range of materials, from standard catalogue carbon steel to special alloys for high-temperature service or corrosive environments. The heat treatment and surface finish are decisive for the service life of the stack.
— Available materials
Carbon spring steel
General industrial use · catalogue standard
Stainless steel
Corrosion · food · chemical · pharmaceutical
Special alloys
High temperature · extreme environments · aerospace
— Treatments and finishes
- Pre-setting Mandatory per DIN 2093 · ensures dimensional stability under load
- Austenitizing Better elastic qualities · maximum service life in dynamic applications
- Hardening + tempering + shot peening Alternative to austenitizing · excellent fatigue resistance
- Phosphating · bluing Base anti-corrosion protection · catalogue standard finish
- Delta·Tone / zinc-lamellar coating Advanced resistance to salt corrosion · exterior automotive
09
Industrial applications of disc springs
DIN 2093 / DIN EN 16983 disc springs are used in a wide variety of industrial applications where a high axial force is required in a small space.
Automotive and heavy machinery
Preload · clutches · valves
Bearing preload, clutch systems, safety valves and pneumatic / hydraulic actuators. The high force per volume allows the spring to be integrated inside valve bodies and transmission housings.
Oil and gas
Flange joints · HP valve sealing
Long series stacks in pipe flanges with variable pressure and thermal expansion. They keep the sealing force constant throughout the service cycle.
Energy · turbines and generators
From 150 — 400 mm · HT steels
Compensation of thermal expansion in boiler structures, steam pipe supports and flexible suspension systems. Alloy steels for high-temperature service.
Precision engineering
Tooling · presses · clamping
Tool-holding systems in spindles (drill bit, drill, milling cutter), die preload, hydraulic collets and presses. The spring provides fail-safe clamping in the event of hydraulic pressure loss.
Construction and infrastructure
Pre-tensioned anchors · damping
Elastomeric bearings, vibration dampers, pre-tensioned anchors for steel structures and compensating springs in expansion joints.
Chemical and pharmaceutical industry
Flanges · constant-pressure seals
Flanges and seals in piping with constant-pressure requirements. Stainless steel versions in AISI 301 / 316 for corrosive environments and CIP cleaning.
10
Frequently asked questions
01 What is the difference between a Series A, B and C disc spring per DIN 2093?
The difference lies in the ratio between the external diameter and the material thickness (De/t). Series A (De/t ≈ 18) generates the highest force for a given diameter; Series B (De/t ≈ 28) medium force; and Series C (De/t ≈ 40) the lowest force. The higher the De/t ratio, the flatter and more flexible the spring. The choice between series depends on the required force and the axial space available in the housing.
02 When is it necessary to use a disc spring with contact surfaces?
The DIN 2093 / DIN EN 16983 standard recommends contact surfaces when the material thickness exceeds 6 mm. Contact surfaces increase the contact area between stacked pieces, improving stress distribution and reducing wear in dynamic applications. In parallel stacks it is essential to consider the reduced thickness t′ (instead of t) to correctly calculate the total height of the assembly.
03 How is a series and parallel disc spring stack calculated?
In a series stack (springs alternating orientation) the force equals that of a single spring and the total travel is multiplied by the number of pieces. In parallel (same orientation) the travel is that of a single spring and the force is multiplied by the number of pieces, with a correction for friction between pieces. For combined stacks, the Surisa calculation program obtains the full load-deflection curve with hysteresis correction.
04 Which lubricant is recommended for DIN 2093 disc springs?
Depending on the working environment, oils, greases or molybdenum disulphide (MoS₂) pastes can be used. The key is to ensure lubrication both between the pieces of the stack and between these and the guiding element. For applications where friction control is critical, there are special guiding solutions with rings or balls between pieces that replace sliding contact with rolling contact.
05 Is it possible to manufacture disc springs in special materials or outside the DIN 2093 sizes?
Yes. In addition to the standard catalogue in carbon spring steel (51CrV4, Ck67, C75S), Surisa manufactures disc springs in AISI 301, 302 and 316 stainless steel, as well as in special alloys such as Inconel, Hastelloy or Nimonic for high-temperature service. Diameters and thicknesses outside the standardised series are also manufactured, always respecting the geometry defined by the standard.
06 Why does a disc spring stack lose force over time?
Any disc spring subjected to a constant compression load over a prolonged period experiences a gradual loss of force due to material relaxation. To minimise it, all springs manufactured to DIN 2093 / DIN EN 16983 undergo a pre-setting process: they are fully flattened and any that do not recover their initial height are discarded. As a reference, a stack tends to lose around 5% of force in the first two weeks after assembly, stabilising from then on.
Let's talk about your project
Tell us about your use case and our engineering team will help you choose the optimal solution.