Standard Disc Spring
(Spring Washer) Materials

Ck 67 (DIN 1.1231): Ck 67 is the most inexpensive spring steel for low stress applications, but is no longer used by Mubea for Group 1 belleville springs and washers.
51 CrV 4 (DIN 1.8159): 51 CrV 4 is the most regularly used disc spring material. 51 CrV 4 offers the best spring characteristics in the temperature range of - 15 °C to + 150 °C, due to high alloy content. The low end of the temperature spectrum can reach - 25 °C, if a reduction of durability is permissible. The high end of the spectrum can reach+ 200 °C, with hot presetting of the material. In addition, the 51 CrV 4 material has a lower level of relaxation than non-alloy steels.
51 CrMoV 4 (DIN 1.7701): 51 CrMoV 4 has comparable material characteristics to 51 CrV 4. The addition of molybdenum (Mo) enables disc springs with a thickness up to 40 mm to be easily through hardened. The 51 CrMoV 4 material is more apt for applications with a operating temperature range of 0 °C to -20 °C, due to its higher ductility than 51 CrV 4.