Disc Spring Tolerances:
The following maximum deviations are laid down in DIN 2093. In general IIS also applies these tolerances to special sizes, however, if they deviate greatly from the DIN, wider tolerances must be specified.They are valid for all Disc Springs as per the DIN and our works standards.
This applies to our ball-bearing Disc Springs. If closer tolerances are required than those tolerances in DIN 2093, please consult us.
Tolerances:
As cost is a major consideration, springs must be produced in the most economical manner. Also, it is wise to apply tolerances only to functional requirements and dimensions. Specified tolerances, therefore, should be generous enough to permit the fabrication of acceptable springs by ordinary production methods. Another recommendation for the product designers: If the standard drawing forms have tolerance boxes for machined dimensions they are almost sure to be impractical for springs.This practice gives the spring maker an opportunity to make adjustments to make compensate for the allowable variations present in the size and mechanical properties of all spring materials. Delete them and apply realistic tolerances to the mandatory spring requirements.
Free Height Tolerances
| Group | t | Tolerance for t (mm) |
| 1 | <1.25 | +0.10/-0.05 +0.03/-0.09 |
| 2 | 1.25 to 2.0 >2.0 to 3.0 >3.0 to 6.0 | +0.15/-0.08 +0.20/-0.10 +0.30/-0.15 |
| 3 | >6.0 to 14.0 | +0.30/-0.30 |
Thickness Tolerances
| Group | t or t' (mm) | Tolerance for t (mm) |
| 1 | 0.2 to 0.6 >0.6 to <1.25 | +0.02/-0.06 +0.03/-0.09 |
| 2 | 1.25 to 3.8 >3.8 to 6.0 | +0.04/-0.12 +0.05/-0.15 |
| 3 | >6.0 to 14.0 | +0.10/-0.10 |
Load Tolerances
The static load F must be determined at the proof test height of the Disc Spring. Calculation must be based upon the nominal material thickness of the Disc Spring t and not with the reduced material thickness t' . Measurements must be made during loading of the Disc Spring. The loading plates must be hardened, ground & polished. appropriate lubrication must be used during the testing
The tolerances on spring load
| Group | t | Tolerance for t (mm) |
| 1 | <1.25 | +0.25.0 - 7.5 |
| 2 | 1.25 to 3.0 | +0.15 |
| >3.0 to 6.0 | - 7.5 | |
| 3 | >6.0 to 14.0 | + 5.0 |
To ensure the specified spring forces, DIN 2093 allows the overall height tolerance to be slightly exceeded.
Theoretical vs Measured Characteristic of a Disc Spring
The characteristic of the individual Disc Spring is non-linear. Its shape depends on the ratio ho/t. When S/ho>0.75 the characteristic in practice again departs increasingly from the theoretical because the Disc Springs roll upon one another or upon the supporting surface and this leads to a continuous shortening of the lever arm. At the lower portion of the deflection range the characteristic in practice depart slightly from the theoretical. For this reason, the spring force is only indicated at Ss=0.75 ho in DIN 2093.
