ISO 7089Flat washer

ISO 7089 M10 Flat washer

ISO 7089 M10 is a flat washer, sized for M10 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 M10d2 20⌀10.5h 2
ISO 7089 M10 — Flat washerNominal dimensions in mm · Not to scale
ThreadM10
Inside Ø d110.5 mm
Outside Ø d220 mm
Thickness h2 mm

Dimensions

Standard
ISO 7089
Type
Flat washer
Size
M10
For bolt size
M10
Total height h
2 mm
Inside diameter d1
10.5 mm
Outside diameter d2
20 mm

Nominal values in millimetres as published in ISO 7089. Estimated weight 3.573 g per piece in steel (3.596 g in stainless), calculated from the nominal geometry — real parts vary with tolerance and head chamfers.

Other lengthsISO 7089 M10

All M10 specifications
M10

Interchangeability

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

Equivalent standardDIN 125 AFlat Washer — Normal Series, 140 HVComparisonISO 7089 vs DIN 125 AField-by-field differences and a substitution verdict

Choosing and fitting this size

ISO 7089 M10 is a washer with a 10.5 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.