Flat Washer Standards

DIN125A ~ ISO7089 

DIN433 ~  ISO7092 

DIN9021 ~ ISO7093

Note: The following table is provided for guidance only as there are often dimensional variations between standards.

Thread Inside Diameter Outside Diameter Thickness Standards
M1 1.1/1.25 2.3/2.5 0.2/0.4 DIN433 BS4320A
M1.2 1.3/1.45 2.8/3 0.2/0.4 DIN433 BS4320A
M1.4 1.5/1.65 2.8/3 0.2/0.4 DIN433 BS4320A
M1.6 1.7/1.85 3.2/3.5 0.25/0.4 DIN433 ISO7092
1.7/1.85 3.7/4 0.25/0.4 DIN125A ISO7089
        BS4320A
1.8/2.05 3.25/4 0.2/0.4 ISO7091 ISO7092
M2 2.2/2.35 4.2/4.5 0.25/4 DIN433
2.2/2.35 4.7/5 0.2/0.4 DIN125A ISO7089
        BS4320A
2.4/2.6 3.25/4 0.2/0.4 ISO7091  
M2.5 2.7/2.85 4.7/5 0.45/0.55 DIN433 ISO7092
2.7/2.85 5.7/6 0.45/0.55 DIN125A ISO7089
2.9/3.2 5.3/6 0.4/0.6 ISO7091  
2.7/2.85 6.2/6.5 0.4/0.6 BS4320A  
2.7/2.85 7.7/8 0.7/0.9 DIN9021  
M3 3.2/3.4 5.7/6 0.45/0.55 DIN433 SO7092
3.2/3.4 6.7/7 0.45/0.55 DIN125A ISO7089
3.4/3.7 6/7 0.4/0.6 ISO7091  
3.2/3.4 6.7/7 0.4/0.6 BS4320A  
3/3.2 8.7/9 0.7/0.9 DIN9021 ISO7093
M3.5 3.7/3.9 6.7/7 0.45/0.55 DIN433 ISO7092
3.7/3.9 6.7/7 0.4/0.6 BS4320A  
3.7/3.9 7.7/8 0.45/0.55 DIN125A ISO7089
3.7/3.9 10.6/11 0.7/0.9 DIN9021 ISO7093
M4 3.7/3.9 6.7/7 0.45/0.55 DIN433 ISO7092
3.7/3.9 6.7/7 0.4/0.6 BS4320A  
3.7/3.9 7.7/8 0.45/0.55 DIN125A ISO7089
3.7/3.9 10.6/11 0.7/0.9 DIN9021 ISO7093
M5 5.3/5.5 8.7/9 0.9/1.1 DIN433 ISO7092
5.3/5.5 9.7/10 0.7/0.9 BS4320B  
5.3/5.5 9.7/10 0.9/1.1 DIN125A ISO7089
      BS4320A  
5.3/5.5 12/12.5 0.9/1.1 BS4320C  
5.3/5.5 14.6/15 1/1.4 DIN9021 ISO7093
5.5/5.8 9/10 0.8/1.2 DIN126 ISO7091
M6 6.4/6.6 10.6/11 1.4/1.8 DIN433 ISO7092
6.4/6.6 11.6/12 1.4/1.8 DIN125A ISO7089
6.4/6.7 12/12.5 0.7/0.9 BS4320B  
6.4/6.7 12/12.5 1.4/1.8 BS4320A  
6.4/6.4/ 13.6/14 0.7/0.9 BS4320D  
6.4/6.7 13.6/14 1.4/1.8 BS4320C  
6.4/6.7 17.6/18 1.4/1.8 DIN9021 ISO7093
6.6/7 11/12    1.3/1.9 DIN126 ISO7091
M8 8.4/8.6 14.6/15 1.4/1.8 DIN433 ISO7092
8.4/8.6 15.6/16 1.4/1.8 DIN125A ISO7089
8.4/8.7 16.6/17 0.9/1.1 BS4320B  
8.4/8.7 16.6/17 1.4/1.8 BS4320A  
8.4/8.7 20.5/21 0.9/1.1 BS4320D  
8.4/8.7 20.5/21 1.4/1.8 BS4320C  
M10 10.5/10.8 17.6/18 1.4/1.8 DIN433 ISO7092
10.5/10.8 19.5/20 1.8/2.2 DIN125A ISO7089
10.5/10.9 20.5/21 1/1.45 BS4320B  
10.5/10.9 20.5/21 1.8/2.2 BS4320A  
10.5/10.9 23.5/24 1/1.45 BS4320D  
10.5/10.9 23.5/24 1.8/2.2 BS4320C  
10.5/10.8 29.5/30 2.3/2.7 DIN9021 ISO7093
11/11.5 18.8/20 1.7/2.3 DIN9021 ISO7091
M12 13/13.3 19.5/20 1.8/2.2 DIN433 ISO7092
13/13.4 23.5/24 1.4/1.8 BS4320B  
13/13.4 23.5/24 2.3/2.7 BS4320A DIN125A
        ISO7089
13/13.4 27.5/28 1.4/1.8 BS4320D  
13/13.4 27.5/28 2.3/2.7 BS4320C  
13/13.3 36.4/37 2.3/2.7 DIN9021 ISO7093
13.5/14 22.8/24 2.2/2.8 DIN126 ISO7091
M16 17/17.3 27.5/28 2.3/2.7 DIN433 ISO7092
17/17.3 29.5/30 2.7/3 DIN125A ISO7089
17/17.4 29.5/30 1.8/2.2 BS4320B  
17/17.4 29.5/30 2.7/3.3 BS4320A  
17/17.4 33/34 1.8/2.2 BS4320D  
17/17.4 33/34 2.7/3.3 BS4320C  
17/17.3 49.4/50 2.7/3.3 DIN9021 ISO7093
17.5/18 28.8/30 2.4/3.6 DIN126  
M20 21/21.5 33.4/34 2.7/3.3 DIN433 ISO7092
21/21.5 36/37 1.8/2.2 BS4320B ISO7091
21/21.5 36.5/37 2.7/3.3 DIN125A ISO7089
21/21.5 36/37 2.7/3.3 BS4320A  
21/21.5 38/39 1.8/2.2 BS4320D  
21/21.5 38/39 2.7/3.3 BS4320C  
22/22.5 35.5/37 2.4/3.6 DIN126 ISO7091
20/20.6 54/56 3.4/4.6 DIN9021 ISO7093


Note: Due to the fact that fastening applications differ greatly, the above information is for guidance only and is correct to the best of our knowledge. The customer must satisfy themselves with the performance of the fastener and validity of the data. TR Fastenings will not be held responsible for any failure that may occur from the use of this information.