Self Tapping Screws - torque data

 

 

Metric

Types AB,B,BT & Y   Application test plates for types AB,B,BT & Y
Screw size Minimum torsional load Screw size Plate thickness Hole diameter
mm No. Nm lbf in mm No. mm in. mm in.
2.2 2 0.49 4 2.2 2 1.22 0.048 1.93 0.076
2.9 4 1.47 13 2.9 4 1.22 0.048 2.44 0.096
3.5 6 2.74 24 3.5 6 2.03 0.08 2.95 0.116
4.2 8 4.41 39 4.2 8 2.03 0.08 3.46 0.136
4.8 10 6.27 56 4.8 10 3.18 0.125 4.05 0.159
5.5 12 10.78 88 5.5 12 3.18 0.125 4.75 0.188
6.3 14 15.98 142 6.3 14 4.75 0.187 5.5 0.217
7 16 34.71 290 7 16 4.75 0.187 6.91 0.272
 

 

Inch

Unified threads types D & T   Application test plates for types D & T
Screw size Minimum torsional load Screw size Plate thickness Hole diameter
No. Threads per Inch lbf in No. Threads per Inch mm in. mm in.
4 40 13 4 40 2.77 0.109 2.4 0.096
4 48 15 4 48 2.77 0.109 2.44 0.096
6 32 23 6 32 3.58 0.141 3.05 0.12
6 40 27 6 40 3.58 0.141 3.05 0.12
8 32 42 8 32 3.58 0.141 3.74 0.147
8 36 47 8 36 3.58 0.141 3.74 0.147
10 24 56 10 24 4.75 0.187 4.4 0.173
10 32 74 10 32 4.75 0.187 4.5 0.177
1/4" 20 140 1/4" 20 6.35 0.25 5.79 0.228
1/4" 28 179 1/4" 28 6.35 0.25 5.94 0.234
5/16" 18 306 5/16" 18 7.92 0.312 7.36 0.29
5/16" 24 370 5/16" 24 7.92 0.312 7.5 0.295
 

The minimum torsional loads shown for unified sizes are based on BS 1580, an imperial unit's standard.