Disc Springs Above 6mm thick

The larger diameter disc springs, in excess of 6mm thickness, of necessity have larger diametral clearances. To minimise the possibility of bearing point misalignment when disc springs are stacked in series i.e. "back-to-back", flats are machined on the upper inside and lower outside diameter edges. However, the introduction of this bearing flat also moves the position of the points of contact, thus reducing the effective radial width of the disc spring and increasing its stiffness. To ensure that disc springs with bearing flats have similar characteristics to the same size disc springs without flats, the nominal thickness is reduced

For more information on Disc Springs Above 6mm thick talk to Belleville Springs