Metric Flat Washers

Metric Flat Washers are used to increase the bearing surface area of a bolt/screw head or nut possibly because the hole is oversized or the mating material is soft. They are thin disks with a concentric hole matched to the size of the fastener with which they are mated. Small Pattern Flat Washers are used with screws that have a small diameter head like Cheese Head and Socket Head Cap Screws. Fender Washers have an outside diameter that is about 3 times their screw (nominal) size. Use Class 100 HV steel washers with fasteners Class 6/Class 6.8 and below; 140 HV below Class 8/Class 8.8; 200 HV is used with Class 8/Class 8.8 and below; and 300 HV steel is suitable for Class 10/Class 10.9 and below. Steel and stainless steel are available along with plain and zinc plated finishes.

DIN 125 A Flat Washer
SIZE: M1 - M80 | MATERIAL: Class 140 HV, 200 HV, 300 HV Steel – A2, A4 Stainless Steel | FINISH: Plain, Zinc

DIN 433 Small Pattern Flat Washer
SIZE: M1 - M24 | MATERIAL: Class 140 HV Steel – A2, A4 Stainless Steel | FINISH: Plain, Zinc

DIN 9021 Fender Washer (~3d OD)
SIZE: M2 - M24 | MATERIAL: Class 100 HV, 140 HV Steel – A2, A4 Stainless Steel | FINISH: Plain, Zinc