Countersunk Nib.png
Countersunk Nib
A Countersunk Nib is a bolt with a nib on one side to prevent the bolt from turning when fastening the nut. 
Diameter
(d)
ds
 
B
 
P
 
a
 
E
 
r
 
D
 
M10
M12
10.00-9.78
12.00-11.73
6.3-5.1
1.50
1.75
3.5
4.0
2.5-2.1
3.0-2.6
0.8
1.3
20.0-17.0
24.0-20.4
7.5-6.2
M16
16.00-15.73
10.0-8.3
2.00
5.0
4.0-3.5
1.3
32.0-27.2
M20
20.00-19.67
2.50
12.5-10.4
7.0
5.0-4.5
1.8
40.0-34.0
Nib Drawing.jpg