DIN 125 AFlat washer

DIN 125 A M3 Flat washer

DIN 125 A M3 is a flat washer, sized for M3 bolts. DIN version of the plain flat washer. Form A is the standard 140 HV hardness range, which is lower than the 200 HV of the ISO series.

Dimensioned drawing — DIN 125 A M3d2 7⌀3.2h 0.5
DIN 125 A M3 — Flat washerNominal dimensions in mm · Not to scale
ThreadM3
Inside Ø d13.2 mm
Outside Ø d27 mm
Thickness h0.5 mm

Dimensions

Standard
DIN 125 A
Type
Flat washer
Size
M3
For bolt size
M3
Total height h
0.5 mm
Inside diameter d1
3.2 mm
Outside diameter d2
7 mm

Nominal values in millimetres as published in DIN 125 A. Estimated weight 0.119 g per piece in steel (0.12 g in stainless), calculated from the nominal geometry — real parts vary with tolerance and head chamfers.

Other lengthsDIN 125 A M3

All M3 specifications
M3

Interchangeability

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

Equivalent standardISO 7089Flat Washer — Normal Series, 200 HVComparisonDIN 125 A vs ISO 7089Field-by-field differences and a substitution verdict

Choosing and fitting this size

DIN 125 A M3 is a washer with a 3.2 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.