Test disc springs according to DIN EN 16983
DIN EN 16983 describes Quality requirements and dimensions for disc springsFor practical testing, the spring force at defined test heights, the corresponding spring deflection, and the resulting force-displacement characteristic are particularly relevant. To ensure that these values can be determined reliably and reproducibly, the testing machine, force measuring system, displacement measurement, and testing tools must be matched to the specific disc spring, the intended force range, and the expected spring deflection.
The most important points about DIN EN 16983 in brief
- DIN EN 16983 deals with quality requirements and dimensions of disc springs and has replaced the earlier DIN 2093 with unchanged technical content.
- Key test parameters include spring force, spring travel and the resulting force-displacement characteristic curve.
- Spring forces must always be assigned to a clearly defined test height or deformation; in the standard, the specified force value refers to the test height lP = l0 − 0,75·h0.
- Reproducible results require precise force measurement, high-resolution displacement measurement, plane-parallel pressure surfaces and suitable testing tools.
- Universal testing machines can be configured with suitable pressure plates, force transducers and measuring systems for testing individual disc springs, spring packs and spring columns.
- The specific test procedure depends on the respective disc spring, the defined target values and the requirements from the drawing, test instructions or delivery specification.
What does DIN EN 16983 regulate?
DIN EN 16983 specifies quality requirements and dimensions for disc springs. These include requirements for materials and manufacturing processes, dimensional and form tolerances, spring force tolerances, and specifications for permissible relaxation and service life depending on the load. The standard also distinguishes three dimensional series (A, B, and C) with different ratios of outer diameter to spring thickness, as well as three production groups, primarily based on spring thickness. The aim is to ensure the functionality of disc springs through uniform technical requirements. For practical quality testing, the geometric properties and spring forces at defined test heights are particularly relevant. Depending on the specific testing task, additional standards, drawing specifications, and customer-specific requirements must also be considered.
Scope of the standard
DIN EN 16983 applies to disc springs, i.e., conical, ring-shaped spring elements subjected to axial loads. It is relevant both for testing individual disc springs and for evaluating springs that will later be used in assemblies or spring columns. Typical testing tasks include checking the dimensions and determining the spring force at specified heights or deflections.
Cylindrical helical compression springs, on the other hand, are not covered by the scope of DIN EN 16983. Although both types of springs can be subjected to compression, they differ significantly in terms of geometry, characteristic curve, and test setup. The present test application therefore focuses exclusively on disc springs.
DIN EN 16983 and earlier DIN 2093
DIN EN 16983:2017-09 transposes the earlier DIN 2093:2013-12, with identical technical content, into a European Standard. Accordingly, older drawings, inventory documents, and delivery specifications still frequently contain references to DIN 2093. For current documentation and new specifications, the designation DIN EN 16983 is authoritative.
Therefore, for existing inspection orders, it should be checked which edition of the standard the respective drawing or inspection instruction refers to. This helps avoid misunderstandings when selecting dimensions, tolerances, and inspection conditions.
What properties are tested on disc springs?
During incoming goods inspection, production control, and quality assurance, both the geometric characteristics and the mechanical behavior of disc springs are checked. The focus is on the spring force at defined test heights, the spring deflection, and the resulting spring characteristic curve. Dimensions, hardness, and other quality characteristics can also be checked. Specific limit values and tolerances must be defined based on the applicable standard and the corresponding drawing.
Spring force at defined test height
The spring force is only meaningful in conjunction with a clearly defined test height or deformation. Therefore, spring force and its corresponding test height always form a pair of values, usually specified in drawings and data sheets as F1 and l1 (or L1). In DIN EN 16983, specified spring forces refer to a spring deflection of 75 percent of the internal cone height, corresponding to the test height lP = l0 − 0,75·h0. Here, l0 denotes the free height of the unloaded disc spring and h0 the internal cone height.
The reference point has a practical reason: Above a spring travel of more than 0,75·h0, the characteristic curve becomes increasingly progressive because the points of force application on the contact surfaces shift. Therefore, in practice, the available spring travel is usually only utilized to about 75 to 80 percent. During testing, the force achieved by the disc spring at the specified test height is checked, and it is verified that this value is within the defined tolerances.
Suspension travel and spring characteristic
During loading, the testing machine records the force-displacement curve. This allows for an assessment of whether the disc spring exhibits the expected characteristic curve within its intended operating range and whether specified target values or tolerance ranges are met. Friction between the spring and the contact surfaces generally leads to a visible hysteresis between loading and unloading. This is minimized by suitable lubrication of the contact surfaces, but cannot be completely eliminated and must be taken into account when evaluating the characteristic curve.
Dimensions and geometric properties
Typical dimensional checks include outer diameter, inner diameter, material thickness, free height l0, and clear cone height h0. These characteristics directly influence the spring behavior and are therefore often checked in addition to the force test. Material thickness, in particular, has a strong effect on the spring force because the spring force increases approximately with the cube of the thickness.
Hardness and additional quality characteristics
Depending on the testing requirements, the hardness of the disc spring can also be tested. Spring steels such as Ck67 (material no. 1.1231) are typically used for spring thicknesses up to 1,25 mm, and 50CrV4 (1.8159) for thicknesses above 1,25 mm. The hardness test is generally performed according to... VickersFor thinner springs, a hardness range of 425 to 510 HV10 is typical. Separate hardness testing equipment and the relevant testing or material standards are required for hardness testing. In contrast, testing on a universal testing machine focuses on force, displacement, and spring characteristic.
Procedure for a disc spring test according to DIN EN 16983
For reproducible results, the disc spring, test setup, and test parameters must be clearly defined. The process ranges from correct positioning and controlled advancement to the actual force measurement and documented evaluation of the force and displacement values.
Prepare and position the disc spring
The disc spring is inserted centrally between parallel pressure surfaces. Precise alignment is crucial to prevent tilting, lateral forces, and consequently, inaccurate measurements. The pressure surfaces are typically lubricated with a suitable lubricant to reduce friction between the spring and its support. With unslotted disc springs, it is essential to ensure that any trapped air can escape, as it will otherwise distort the spring's characteristic curve.
Define starting height and test positions
The initial height and test points are taken from the drawing, delivery specification, or test instructions. The reference point for the spring force according to DIN EN 16983 is the test height lP = l0 − 0,75·h0. Additional test positions, for example at 0,25·h0 or 0,5·h0, can be useful for evaluating the characteristic curve. The test software assigns the respective target values for force or spring deflection to the defined positions.
Positioning the disc spring
Before the actual force measurement, it is common practice to pre-tension the spring several times. During this process, the disc spring is loaded repeatedly to the specified setting depth to relieve internal stresses and obtain stable, reproducible force values. The number of pre-tensioning strokes and the setting depth are specified in the test instructions. If pre-tensioning is omitted, the force values typically deviate systematically from the later operating values.
Apply pressure to a disc spring and record the force-displacement curve.
The spring is subjected to controlled loading up to the defined test positions, typically at a constant test speed. The system continuously records the force and deformation and generates the corresponding force-displacement curve. The loading and unloading processes can be recorded separately and compared.
Evaluate and document results
The testing software outputs spring forces, test heights, spring travel, and deviations from stored target values. Additionally, test curves, reports, and series analyses can be generated. The results serve both for release decisions during goods receipt and production control, as well as for long-term trend monitoring in quality assurance.
Testing of individual disc springs, spring assemblies and spring columns
In addition to individual disc springs, spring assemblies and spring columns can also be tested. The arrangement of multiple disc springs significantly alters the force-displacement behavior. With springs stacked in the same direction (spring assembly), the spring forces approximately add up, while the spring displacement corresponds to that of a single spring. With springs stacked in opposite directions (spring column), the spring displacements approximately add up, while the spring force corresponds to that of a single spring. Combined stacking configurations allow for the creation of specifically tailored characteristic curves. The test plan must therefore clearly define whether a single spring or a defined combination is being tested. The number, orientation, and arrangement of the disc springs must be documented, as well as the intended test heights and target forces.
Requirements for a testing machine for disc springs
A testing machine for disc springs must be calibrated to the expected force range and the short deformation paths of the springs. The following features are particularly important for reliable and reproducible results:
- a sufficiently rigid test frame so that the deformation of the test setup does not distort the displacement measurement,
- a force transducer suitable for the force range, calibrated according to DIN EN ISO 7500-1,
- a precise and high-resolution distance measurement,
- Planar printing plates with a suitable surface,
- Suitable testing tools and guides for individual disc springs, spring assemblies or spring columns,
- Test software for recording and evaluating the force-displacement characteristic curve with load and unload branches.
Especially at high forces and small spring travels, even slight deformation of the test setup can affect the measurement result. Therefore, the machine, measuring technology, and fixture should always be designed together for the specific test task.
GALDABINI universal testing machines for disc spring testing
GALDABINI's universal testing machines can be configured with suitable pressure plates, force transducers, and displacement measuring systems for testing disc springs. For lower test forces, the QUANTUM tabletop machines (5 to 100 kN) are suitable, while the QUASAR floor-standing machines (200 to 2000 kN) are ideal for higher forces. This allows for the testing of individual disc springs as well as spring assemblies and spring columns. The testing software LABTEST It records the force-displacement curve, evaluates defined test heights and spring forces, and supports the documented execution of recurring test procedures.
SCHÜTZ+LICHT assists in selecting the appropriate machine capacity, measuring technology, and testing tools for your specific application. Contact us if you wish to automate an existing testing task, upgrade a testing station, or develop a new testing solution for disc springs according to DIN EN 16983. We will work with you to tailor the machine, measuring technology, and fixture to your spring dimensions, expected force range, and documentation requirements.
Frequently asked questions about DIN EN 16983
What does DIN EN 16983 regulate?
DIN EN 16983 describes quality requirements and dimensions for disc springs. For testing, geometric characteristics and spring force at specified test heights are particularly relevant.
What is the difference between DIN EN 16983 and DIN EN 16984?
DIN EN 16983 addresses quality requirements and dimensions of disc springs. DIN EN 16984, on the other hand, deals with their calculation. In practice, both standards are therefore often considered together: DIN EN 16984 supports the design process, while DIN EN 16983 describes requirements for the finished product.
Why must the spring force be measured at a defined test height?
The spring force changes with the deformation of the disc spring. Therefore, a force value is only unambiguously comparable if the corresponding test height or spring deflection is also defined. According to DIN EN 16983, the spring forces are referenced to the test height lP = l0 − 0,75·h0, i.e., to a spring deflection of 75 percent of the internal cone height.
What is the difference between a spring pack and a spring column?
In a spring pack, disc springs are stacked in the same direction. The spring forces add up approximately, while the spring travel corresponds to that of a single spring. In a spring column, disc springs are stacked in alternating directions. The spring travels add up approximately, and the spring force corresponds to that of a single spring. By combining different stacking configurations, specific characteristic curves with desired force-displacement characteristics can be achieved.
Which testing machine is suitable for disc springs?
A suitable universal testing machine offers an appropriate force range, precise force measurement, high-resolution displacement measurement, plane-parallel pressure plates, and a sufficiently rigid test frame. The force measurement should be calibrated according to DIN EN ISO 7500-1. The selection depends on spring force, spring travel, dimensions, and the intended test procedure.
Why are disc springs used before force measurement?
During pre-setting, the disc spring is subjected to repeated loading up to the specified setting depth. This reduces residual stresses, and subsequent force measurements yield reproducible values. Without pre-setting, the measured forces often deviate systematically from the later operating values.
