Flat washers prevent sinking of bearing surfaces,The main role of flat washers is to increase the size of a screw's bearing surface area, and reduce the surface pressure applied on the fastened object.
Size: M1-M36,or non-standard as request&design
Material: Stainless Steel,Alloy steel,Carbon Steel,Brass,Aluminum and So on
Grade:4.8,8.8,10.9,12.9.etc
Standard:GB, DIN, ISO, ANSI/ASTM, BS, BSW, JIS etc
Non-standards :OEM is available, according to drawing or samples
Finish: Plain, black, zinc plated/according to your requirement