Model Engine Company of America

2-18-2022

Suggested Maximum Torque for Screws

This applies to clean and dry parts. A lubricated screw requires less torque than non-lubricated to obtain same clamping force. The values are stated in Inch pounds.

SHCS torque is for quality Socket Head Screws. If you are not sure use mild steel torque.
GLOW PLUG TORQUE IS 20-24 inch pounds.

Always cross torque head screws when tightening. First just let all the screw heads make contact, then tighten slightly in a cross pattern. Then final torque may be applied in a cross torquing pattern.

Screw Size
Pitch
Stainless
Mild Steel
SHCS Steel
2
56
64
2.5
3.0
2.2
2.7
2.5
3.1
3
48
56
3.9
4.4
3.5
4.0
4.0
4.5
4
40
48
5.2
6.6
4.7
5.9
5.3
6.7
5
40
44
7.7
9.4
6.9
8.5
7.8
9.6
6
32
40
9.6
12.1
8.7
10.9
9.8
12.3
8
32
36
19.8
22.0
17.8
19.8
20.2
22.4
10
24
32
22.8
31.7
20.8
29.7
25.9
34.9
1/4
20
28
75
94
65
90
84
105
5/16
18
24
132
142
129
139
149
160
3/8
16
24
236
259
212
232
266
297

 

 
The above information is provided as a guide. Since MECOA/K&B has no way of determining the ability of the individual using and understanding this information, we assume absolutely NO RESPONSIBILITY for any damage to person or property from the use of this information.