ISO 7089Flat washer

ISO 7089 M8 Flat washer

ISO 7089 M8 is a flat washer, sized for M8 bolts. The general purpose flat washer. It protects the clamped surface, bridges oversized holes and spreads load under the head or nut.

Dimensioned drawing — ISO 7089 M8d2 16⌀8.4h 1.6
ISO 7089 M8 — Flat washerNominal dimensions in mm · Not to scale
ThreadM8
Inside Ø d18.4 mm
Outside Ø d216 mm
Thickness h1.6 mm

Dimensions

Standard
ISO 7089
Type
Flat washer
Size
M8
For bolt size
M8
Total height h
1.6 mm
Inside diameter d1
8.4 mm
Outside diameter d2
16 mm

Nominal values in millimetres as published in ISO 7089. Estimated weight 1.829 g per piece in steel (1.841 g in stainless), calculated from the nominal geometry — real parts vary with tolerance and head chamfers.

Other lengthsISO 7089 M8

All M8 specifications

Interchangeability

ISO 7089 is catalogued with DIN 125 A as its equivalent designation. Dimensions are compared field by field rather than assumed identical.

Choosing and fitting this size

ISO 7089 M8 is a washer with a 8.4 mm inside diameter. It sits under a bolt head or nut to spread the clamping load; the inside diameter matches the bolt it is specified for, so the washer and fastener should always be ordered as a pair.

Hardness is the governing property rather than tensile strength: a 200 HV washer suits bolts up to class 10.9, while 140 HV washers are intended for class 8.8 and below. Using a soft washer under a high-grade bolt lets the washer deform before the bolt reaches its preload, which quietly loses clamping force.