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
Delivery
24 h mainland · 3–14 d international
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 springs with bearing surfaces, a distinction must be made between the theoretical material thickness (t) and the reduced thickness (t′), which is the actual spring thickness in the contact area. The difference between t and t′ is relevant when designing a parallel stack, since it directly affects the overall 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 |
| lo | Overall free height · lo = t + ho |
| t′ | Reduced thickness — only in disc springs with contact surfaces |
| ho | Maximum deflection · free travel |
| F(0,75 ho) | Force in N at 75% of maximum deflection — recommended dynamic working load |
Overall height formula: lo = t + ho
FIG · technical dimensions
— Catalogue specifications
- Reference standard DIN 2093 · DIN EN 16983.
- External Ø range (De) 8 – 600 mm in the standard catalog. Custom manufacturing up to 1,000 mm.
- Material thickness (t) 0.2 – 24.0 mm. Bearing 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 displacement equals that of a single piece; the force increases in proportion to the number of units.
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.
Series-parallel combination
Combines the advantages of series and parallel arrangements: increasing the available travel while maintaining high force levels. It also allows springs of different thickness to be combined in the same stack, generating a stepped F/s curve — the thinner springs reach their maximum deflection first and, from that point on, the force required to continue the displacement increases progressively as the stiffness of the remaining stack is higher.
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
06
Guiding and lubrication of the stack
The correct operation of a disc spring stack depends largely on its assembly. The hysteresis produced by friction between the springs themselves and between these and the guide elements can alter the actual force-deflection curve relative to the theoretical one.
— Guiding
The most common method is guidance on the internal diameter by means of a shaft. External guidance by means of a sleeve is also possible, and self-guiding designs exist as well. For the first two options, the tolerances of DIN 2093 / DIN EN 16983 must be observed.
The guide surfaces in contact with the parts must be polished and hardened to a minimum of 55 HRC to a depth of 0.80 mm. In long stacks, flat spacer discs may be required to prevent buckling.
— Lubrication
It is essential both between the springs themselves and between these and the guide. The use of molybdenum disulfide (MoS₂) greases is recommended. For applications where friction is critical, special guiding solutions with rings or balls between the parts are available; these replace traditional guidance and eliminate sliding friction (self-guiding).
— 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
During working cycles, disc springs experience variations in their internal stresses. The amplitude of these variations determines the number of cycles they can withstand before failing by fatigue. For a long service life, it is recommended that they work with a pre-compression of around 15% and a maximum compression that does not exceed 75% of their total deflection.
— 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
The presetting process
Presetting (or controlled plastic pre-deformation) is a process in which the disc spring is compressed to its flat height (s = h₀) —or even beyond— in order to induce compressive residual stresses in the critical zones, improving its in-service behavior. It is carried out after the tempering heat treatment, once the spring has acquired its final mechanical properties. The localized plastic deformation introduces compressive residual stresses in the outer fibers of the most highly stressed zones (especially at the upper and lower inner edge), and can be performed in one or several passes depending on the spring specifications.
Cold presetting. This is the most common method. The spring is compressed at room temperature to its flat height, exceeding the material's elastic limit in a controlled manner. The compressive residual stresses become fixed in the critical zones once the load is removed.
Hot presetting. The spring is compressed to its flat height while held at an elevated temperature —typically between 200 °C and 500 °C depending on the material— for a set time, then cooled in a controlled manner. Compared with cold presetting, it provides:
- Greater dimensional stability against relaxation in service, especially in high-temperature applications.
- Less loss of free height (set) when the spring operates in hot environments.
- Greater effect on high-strength materials (Inconel, stainless steels, special alloys), whose elastic limit is difficult to exceed at room temperature, with a lower risk of surface damage.
- Better fatigue resistance at high temperature, as the residual stresses are more thermally stable.
On the downside, it requires specific controlled-heating equipment and greater process control, which increases the cost compared with cold presetting.
Effects of presetting. Increased load capacity, improved fatigue resistance, reduced set (loss of free height under sustained load) and dimensional stabilization of the spring before it enters service.
Verification. After presetting, the free height (lo) is checked within tolerance according to DIN 2093, along with the force at nominal deflection on a test bench and the absence of cracks or inadmissible marks on the surface.
Presetting does not replace the heat treatment but rather complements it. Its effect is especially significant in Series C springs (higher h₀/t ratio), owing to the greater plastic deformation possible. The choice between cold and hot presetting must be based on the spring material, the service temperature and the dimensional stability requirements of the application.
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
- GEOMET coating 720 hours in salt spray
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
Flanged joints · valves · drilling tools
Series-parallel stacks and individual springs to absorb thermal expansion and/or vibration, extending service / maintenance cycles.
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 clamping systems in spindles (drill bit, drill, milling cutter), die preload, hydraulic clamps and presses.
Construction and infrastructure
Pre-tensioned anchors · damping
Elastomeric mounts, vibration dampers and anchors.
Chemical and pharmaceutical industry
Flanges · constant-pressure seals
Flanged joints and absorption of thermal expansion in cold-hot processes. Stainless steel versions in AISI 301 / 304 / 316 for corrosive environments.
10
Frequently asked questions
01 When is it necessary to use a disc spring with contact surfaces?
DIN 2093 / DIN EN 16983 recommends bearing surfaces when the material thickness exceeds 6 mm. Bearing surfaces increase the contact area between the springs, improving stress distribution and reducing wear in dynamic applications. In parallel stacks it is essential to consider the reduced thickness t′ (instead of t) in order to correctly calculate the overall height of the assembly.
02 How is a series and parallel disc spring stack calculated?
In a series stack (springs opposed, alternating orientation) the force equals that of a single spring and the total displacement is multiplied by the number of pieces. In parallel (same orientation) the displacement is that of a single spring and the force is multiplied by the number of pieces. For combined stacks, Surisa's calculation program obtains the complete force-deflection curve.
03 Which lubricant is recommended for DIN 2093 disc springs?
Lubrication is essential both between the springs themselves and between these and the guide. The use of molybdenum disulfide (MoS₂) greases is recommended. For applications where friction is critical, special guiding solutions with rings or balls between the parts are available; these replace traditional guidance and also the friction (self-guiding).
04 Is it possible to manufacture disc springs in special materials or outside the DIN 2093 sizes?
Yes. In addition to the standard catalog in carbon spring steel (51CrV4, Ck67, C75S), Surisa manufactures disc springs in stainless steel AISI 301, 304 and 316, as well as in special alloys such as Inconel or Nimonic for high-temperature service. They are also manufactured in diameters and thicknesses different from those suggested by the standard.
05 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.