Rust prevention,good meterial,and best quality washer.
Support sample provide.

hex head self drilling screw with washer

Meterial:

steel,stainless steel

Finish:

zinc plated

Size:

3.5,3.9,4.2,4.8,5.5,6.3

Packaging:

in bulk or boxes

Washer meterial:

EPDM,PVC,RUBBER,ECT