Washer used as a spacer, usually were used with bolts and nuts. The material can be steel or stainless steel. Lyco fasteners manufactures spring washer in spring steel size from M3-M36, inch size from #6 to 1-1/2”, heat treated, the hardness between 41-48 HRC and flat washer from M6-M36, inch size from 1/4” to 1-1/2”.