FLAT WASHER
BS 4320
Steel Hardness: 100HV
Finish: Self, Black, Bright Zinc, Hot Dip Galvanized
Dimensions
| Nominal Washer Size |
Inside Diameter (ID) |
Outside Diameter (OD) |
Thickness (s) |
| Min. |
Max. |
Min. |
Max. |
FORM A |
FORM B |
| Nom. |
Max. |
Min. |
Nom. |
Max. |
Min. |
| M3 |
3.2 |
3.4 |
6.7 |
7 |
0.5 |
0.6 |
0.4 |
– |
– |
– |
| M4 |
4.3 |
4.5 |
8.7 |
9 |
0.8 |
0.9 |
0.7 |
– |
– |
– |
| M5 |
5.3 |
5.5 |
9.7 |
10 |
1 |
1.1 |
0.9 |
– |
– |
– |
| M6 |
6.4 |
6.7 |
12.1 |
12.5 |
1.6 |
1.8 |
1.4 |
0.8 |
0.9 |
0.7 |
| M8 |
8.4 |
8.7 |
16.6 |
17 |
1.6 |
1.8 |
1.4 |
1 |
1.1 |
0.9 |
| M10 |
10.5 |
10.9 |
20.5 |
21 |
2 |
2.2 |
1.8 |
1.25 |
1.45 |
1.05 |
| M12 |
13 |
13.4 |
23.5 |
24 |
2.5 |
2.7 |
2.3 |
1.6 |
1.8 |
1.4 |
| (M14) |
15 |
15.4 |
27.5 |
28 |
2.5 |
2.7 |
2.3 |
1.6 |
1.8 |
1.4 |
| M16 |
17 |
17.4 |
29.5 |
30 |
3 |
3.3 |
2.7 |
2 |
2.2 |
1.8 |
| (M18) |
19 |
19.5 |
33.2 |
34 |
3 |
3.3 |
2.7 |
2 |
2.2 |
1.8 |
| M20 |
21 |
21.5 |
36.2 |
37 |
3 |
3.3 |
2.7 |
2 |
2.2 |
1.8 |
| (M22) |
23 |
23.5 |
38.2 |
39 |
3 |
3.3 |
2.7 |
2 |
2.2 |
1.8 |
| M24 |
25 |
25.5 |
43.2 |
44 |
4 |
4.3 |
3.7 |
2.5 |
2.7 |
2.3 |
| (M27) |
28 |
28.5 |
49.2 |
50 |
4 |
4.3 |
3.7 |
2.5 |
2.7 |
2.3 |
| M30 |
31 |
31.6 |
55 |
56 |
4 |
4.3 |
3.7 |
2.5 |
2.7 |
2.3 |
| (M33) |
34 |
34.6 |
59 |
60 |
5 |
5.6 |
4.4 |
3 |
3.3 |
2.7 |
| M36 |
37 |
37.6 |
65 |
66 |
5 |
5.6 |
4.4 |
3 |
3.3 |
2.7 |
| (M39) |
40 |
40.6 |
71 |
72 |
6 |
6.6 |
5.4 |
3 |
3.3 |
2.7 |
| Nominal Washer Size |
Inside Diameter (ID) |
Outside Diameter (OD) |
Thickness (s) |
| Min. |
Max. |
Min. |
Max. |
FORM C |
FORM D |
| Nom. |
Max. |
Min. |
Nom. |
Max. |
Min. |
| M4 |
4.3 |
4.5 |
9.7 |
10 |
0.8 |
0.9 |
0.7 |
– |
– |
– |
| M5 |
5.3 |
5.5 |
12.1 |
12.5 |
1 |
1.1 |
0.9 |
– |
– |
– |
| M6 |
6.4 |
6.7 |
13.6 |
14 |
1.6 |
1.8 |
1.4 |
0.8 |
0.9 |
0.7 |
| M8 |
8.4 |
8.7 |
20.5 |
21 |
1.6 |
1.8 |
1.4 |
1 |
1.1 |
0.9 |
| M10 |
10.5 |
10.9 |
23.5 |
24 |
2 |
2.2 |
1.8 |
1.25 |
1.45 |
1.05 |
| M12 |
13 |
13.4 |
27.5 |
28 |
2.5 |
2.7 |
2.3 |
1.6 |
1.8 |
1.4 |
| (M14) |
15 |
15.4 |
29.5 |
30 |
2.5 |
2.7 |
2.3 |
1.6 |
1.8 |
1.4 |
| M16 |
17 |
17.4 |
33.2 |
34 |
3 |
3.3 |
2.7 |
2 |
2.2 |
1.8 |
| (M18) |
19 |
19.5 |
36.2 |
37 |
3 |
3.3 |
2.7 |
2 |
2.2 |
1.8 |
| M20 |
21 |
21.5 |
38.2 |
39 |
3 |
3.3 |
2.7 |
2 |
2.2 |
1.8 |
| (M22) |
23 |
23.5 |
43.2 |
44 |
3 |
3.3 |
2.7 |
2 |
2.2 |
1.8 |
| M24 |
25 |
25.5 |
49.2 |
50 |
4 |
4.3 |
3.7 |
2.5 |
2.7 |
2.3 |
| (M27) |
28 |
28.5 |
55 |
56 |
4 |
4.3 |
3.7 |
2.5 |
2.7 |
2.3 |
| M30 |
31 |
31.6 |
59 |
60 |
4 |
4.3 |
3.7 |
2.5 |
2.7 |
2.3 |
| (M33) |
31 |
31.6 |
65 |
66 |
5 |
5.6 |
4.4 |
3 |
3.3 |
2.7 |
| M36 |
37 |
37.6 |
71 |
72 |
5 |
5.6 |
4.4 |
3 |
3.3 |
2.7 |
| (M39) |
40 |
40.6 |
76 |
77 |
6 |
6.6 |
5.4 |
3 |
3.3 |
2.7 |
| Nominal Washer Size |
Inside Diameter (ID) |
Outside Diameter (OD) |
Thickness (s) |
| Min. |
Max. |
Min. |
Max. |
FORM F |
| Nom. |
Max. |
Min. |
| M8 |
9 |
9.4 |
20.2 |
21 |
1.6 |
1.9 |
1.3 |
| M10 |
11 |
11.5 |
23.2 |
24 |
2 |
2.3 |
1.7 |
| M12 |
14 |
14.5 |
27.2 |
28 |
2.5 |
2.8 |
2.2 |
| (M14) |
16 |
16.5 |
29.2 |
30 |
2.5 |
2.8 |
2.2 |
| M16 |
18 |
18.5 |
32.8 |
34 |
3 |
3.6 |
2.4 |
| (M18) |
20 |
20.6 |
35.8 |
37 |
3 |
3.6 |
2.4 |
| M20 |
22 |
22.6 |
37.8 |
39 |
3 |
3.6 |
2.4 |
| (M22) |
24 |
24.6 |
42.8 |
44 |
3 |
3.6 |
2.4 |
| M24 |
26 |
26.6 |
48.8 |
50 |
4 |
4.6 |
3.4 |
| (M27) |
30 |
30.6 |
54.5 |
56 |
4 |
4.6 |
3.4 |
| M30 |
33 |
33.8 |
58.5 |
60 |
4 |
4.6 |
3.4 |
| (M33) |
36 |
36.8 |
64.5 |
66 |
5 |
6 |
4 |
| M36 |
39 |
39.8 |
70.5 |
72 |
5 |
6 |
4 |
| (M39) |
42 |
42.8 |
75.5 |
77 |
6 |
7 |
5 |
| Nominal Washer Size |
Inside Diameter (ID) |
Outside Diameter (OD) |
Thickness (s) |
| Min. |
Max. |
Min. |
Max. |
FORM G |
| Nom. |
Max. |
Min. |
| M5 |
5.5 |
5.8 |
14.2 |
15 |
1.6 |
1.9 |
1.3 |
| M6 |
6.6 |
7 |
17.2 |
18 |
2 |
2.3 |
1.7 |
| M8 |
9 |
9.4 |
23.2 |
24 |
2 |
2.3 |
1.7 |
| M10 |
11 |
11.5 |
29.2 |
30 |
2.5 |
2.8 |
2.2 |
| M12 |
14 |
14.5 |
34.8 |
36 |
3 |
3.6 |
2.4 |
| (M14) |
16 |
16.5 |
40.8 |
42 |
3 |
3.6 |
2.4 |
| M16 |
18 |
18.5 |
46.8 |
48 |
4 |
4.6 |
3.8 |
| (M18) |
20 |
20.6 |
52.5 |
54 |
4 |
4.6 |
3.4 |
| M20 |
22 |
22.6 |
58.5 |
60 |
5 |
6 |
4 |
| (M22) |
24 |
24.6 |
64.5 |
66 |
5 |
6 |
4 |
| M24 |
26 |
26.6 |
70.5 |
72 |
6 |
7 |
5 |
| (M27) |
30 |
30.6 |
79 |
81 |
6 |
7 |
5 |
| M30 |
33 |
33.8 |
88 |
90 |
8 |
9.2 |
6.8 |
| (M33) |
36 |
36.8 |
97 |
99 |
8 |
9.2 |
6.8 |
| M36 |
39 |
39.8 |
106 |
108 |
10 |
11.2 |
8.8 |
| (M39) |
42 |
42.8 |
115 |
117 |
10 |
11.2 |
8.8 |
