Basic dimensions for Form A Washers (BS 4320 / DIN 125 Part 1)

BS 4320 / DIN 125-1: Basic dimensions Form A washers for selected sizes

Nominal size Inside diameter (d1) Outside diameter (d2) Thickness (s)
min. BS 4320 max. DIN 125-1 max. BS 4320 min. BS 4320 max. DIN 125-1 min. DIN 125-1 max. min. max.
M5 5.3 5.5 5.48 9.7 10 9.64 10 0.9 1.1
M6 6.4 6.7 6.62 12.1 12.5 11.57 12 1.4 1.8
M8 8.4 8.7 8.62 16.6 17 15.57 16 1.4 1.8
M10 10.5 10.9 10.77 20.5 21 19.48 20 1.8 2.2
M12 13.0 13.4 13.27 23.5 24 23.48 24 2.3 2.7
M16 17.0 17.4 17.27 29.5 30 29.48 30 2.7 3.3
M20 21 21.5 21.33 36.2 37 36.38 37 2.7 3.3
M24 25 25.5 25.33 43.2 44 43.38 44 3.7 4.3
Dimensions in millimetres

Whilst the information is provided in good faith, Andrews Fasteners Ltd are not under any responsibility or liability in respect of errors or information that was found to be incorrect or for any reliance the user may place on it.

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