Washer (hardware) - Standard Metric Flat Washers Sizes

Standard Metric Flat Washers Sizes

Washers of standard metric sizes are listed in the table below. Measurements in the table refer to the dimensions of the washers as described by the drawing.

Nominal screw
sizes M (mm)
Screw pitch
thread P (mm)
Internal (Inside) diameter
hole d1 (mm)
External (Outside) diameter
d2 (mm)
thickness
H (mm)
1st
choice
2nd
choice
coarse fine
1 0.25 1.1 3 0.3
1.2 0.25 1.3 3.5 0.3
1.4 0.3 1.5 4 0.3
1.6 0.35 1.7 4 0.3
1.7 1.8 4.5 0.3
1.8 0.35
2 0.4 2.2 5 0.3
2.5 0.45 2.7 6 0.5
2.6 2.8 7 0.5
3 0.5 3.2 7 0.5
3.5 0.6 3.7 8 0.5
4 0.7 4.3 9 0.8
5 0.8 5.3 10 1
6 1 0.75 6.4 12 1.6
7 1 7.4 14 1.6
8 1.25 1 8.4 16 1.6
10 1.5 1.25 or 1 10.5 20 2
12 1.75 1.5 or 1.25 13 24 2.5
14 2 1.5 15 28 2.5
16 2 1.5 17 30 3
18 2.5 2 or 1.5 19 34 3
20 2.5 2 or 1.5 21 37 3
22 2.5 2 or 1.5 23 39 3
24 3 2 25 44 4
27 3 2 28 50 4
30 3.5 2 31 56 4
33 3.5 2 34 60 5
36 4 3 37 66 5
39 4 3 40 72 6
42 4.5 3 43 78 7
45 4.5 3 46 85 7
48 5 3 50 92 8
52 5 4 54 98 8
56 5.5 4 58 105 9
60 5.5 4 62 110 9
64 6 4 66 115 9
68 70 120 10
72 74 125 10
76 78 135 10
80 82 140 12
85 87 145 12
90 93 160 12
100 104 175 14

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