Bearing PreLoad Disc Springs: Slotted Type
30 different sizes from 9.8mm up to 94.5mm outside diameter
This range of bearing preload disc springs (washers) have a slotted inside profile which gives a different force/deflection profile to plain type preload disc springs.
These preload disc springs are manufactured from Carbon Steel with a zinc phosphate and oiled finish providing a good selection of dimensions to suit most standard roller bearings.

Bearing PreLoad Disc Springs: Plain Type
65 different sizes from 9.8mm up to 358mm outside diameter
With dimensions to suit most standard roller bearings (radial ball bearings), this range of plain bearing preload disc springs are manufactured from Carbon Steel with a zinc phosphate and oiled finish.
The preload disc springs (or washers) assist in maintaining positioning accuracy of the bearing (with no end play) and also minimise vibration and shaft deflections. Correct preloading will also increase bearing rigidity and negate excessive running noise.