■ Unit : mm Unit : mm

SizeMinor diameter of internal threads (D1)Bored hole size ( ref.)
18.1
18.6
19.09
19.6
20.1
20.6
21.09
21.1
22.1
22.6
23.09
23.1
23.6
24.09
24.6
24.1
25.1
25.6
26.09
26.1
26.6
27.09
26.6
27.1
28.1
28.6
29.09
30.1
30.6
29.6
30.1
31.1
31.6
33.6
32.1
33.1
34.1
34.6
SizeMinor diameter of internal threads (D1)Bored hole size ( ref.)
36.6
35.1
36.1
37.1
37.6
37.1
38.1
38.6
37.6
38.1
39.1
40.1
40.6
40.6
41.1
42.1
43.1
43.6
43.1
44.1
45.1
46.1
46.6
47.1
48.1
48.6
M52×547.29746.58747.1
M52×448.27047.67048.1
M52×349.25248.75249.1
M52×250.21049.83550.1
M52×1.550.67650.37650.6
M55×451.27050.67051.1
M55×352.25251.75252.1
M55×253.21052.83553.1
M55×1.553.67653.37653.6
M56×5.550.79650.04650.6
M56×452.27051.67052.1
M56×353.25252.75253.1
M56×254.21053.83554.1
M56×1.554.67654.37654.6
  • D1: Minor diameter of 6H internal thread. The Minor diameters D1 shown in ( ) are of 5H for coarse threads and of 4H
  • 5H for fine threads.