Classification according to DIN 2093

Disc springs are standardised according to DIN 2092 (Disc Springs, Calculation) and DIN 2093 (Disc springs, Calculation, Dimensions, Quality Requirements). They are classified into 3 groups:

• Group 1: Disc thickness, t, less than 1.25 mm
• Group 2: Disc thickness, t, from 1.25 mm to 6 mm
• Group 3: Disc thickness, t, over 6 mm up to 14 mm

Fig. A: Springs of Groups 1 and 2 without contact surfaces

Fig. B: Springs of Group 3 with contact surfaces

Group 1 and 2 springs are manufactured without contact surfaces (Fig. A). Group 3 springs are manufactured with contact surfaces (Fig. B).

The requirements of parts manufactured to DIN 2093 are summarised in the table below:

Group	Manufacturing Method	Surface Finish**)
		Upper and lower surfaces µm	Inner and outer edges µm
1	stamped, cold-formed, edges rounded	Ra < 3,2	Ra < 12,5
2*)	stamped, cold-formed, De and Di turned, edges rounded	Ra < 6,3	Ra < 6,3
	fine-blanked, cold-formed, edges rounded	Ra < 6,3	Ra < 6,3
3	cold- or hot-formed, turned on all sides , edges rounded	Ra < 12,5	Ra < 12,2

*) Unless otherwise specified, the manufacturing process is left to the discretion of the manufacturer (see Section 5 in DIN 2093).

**) The specified values do not apply to shot-peened disc springs.

Other manufacturing methods such as laser-beam cutting or water-jet cutting, etc. can be used for the production of special disc springs In addition to disc springs with a rectangular cross-section and circular edges as discussed so far, there are the following types:

• disc springs with a trapezoidal lateral surface cross-section and
• disc springs with slots.

Whereas the former are not in wide spread use, disc springs with slots are used extensively in couplings and transmissions. These two types of springs are not covered in the present publication. Mubea engineers are available to answer questions related to the design and manufacture of slotted springs.