ISO 14581

Hexalobular socket countersunk head screws

On the Image:
a) Screws without shoulder, M2~M4
b) Fully threaded screws with shoulder, M5~M10
c) Partially threaded screws with shoulder, M5~M10

tech-iso14581




Screw Thread
d		 M2 M2.5 M3
P Pitch 0.4 0.45 0.5
dk theoretical max 4.4 5.5 6.3
actual max=nominal size 3.8 4.7 5.5
min 3.5 4.4 5.2
k max 1.2 1.5 1.65
x max 1 1.1 1.25
Socket No. T6 T8 T10
A Ref. 1.75 2.4 2.8
t max 0.64 0.79 0.83
min 0.51 0.66 0.7
Length of Thread b 25 25 25

Screw Thread
d		 (M3.5) M4 M5
P Pitch 0.6 0.7 0.8
dk theoretical max 8.2 9.4 10.4
actual max=nominal size 7.3 8.4 9.3
min 6.94 8.04 8.94
k max 2.35 2.7 2.7
x max 1.5 1.75 2
Socket No. T15 T20 T25
A Ref. 3.35 3.95 4.5
t max 1.32 1.53 1.51
min 1.16 1.14 1.12
Length of Thread b 25 38 38

Screw Thread
d		 M6 M8 M10
P Pitch 1 1.25 1.5
dk theoretical max 12.6 17.3 20
actual max=nominal size 11.3 15.8 18.3
min 10.87 15.37 17.78
k max 3.3 4.65 5
x max 2.5 3.2 3.8
Socket No. T30 T45 T50
A Ref. 5.6 7.95 8.95
t max 1.78 2.54 2.8
min 1.39 2.15 2.41
Length of Thread b 38 38 38



All information is strictly informative