A Flat / Plain washer is a thin plate (typically disk-shaped) with a hole (typically in the middle) that is normally used to distribute the load of a threaded fastener. High-quality cap screws require hardened steel washers to prevent the loss of pre-load. These washers are also important for preventing galvanic corrosion, particularly by insulating steel screws from aluminum surfaces.

Standard:

DIN 125, DIN 126, DIN 134, DIN 433, DIN 7989, ISO 7089, ISO 7091, F844, 14399-6, F436, F436M, BS 4320

Dia Range:

Metric Size: M06 TO M150
Imperial Size: 1/4” TO 6”