Godwin HS150 - 10.4 Fastener Torques

Book No.: 95-0014-0000/A OPERATOR
Issue: 06 HANDBOOK
Page 29 of 30
10.4 Fastener Torques
The following tables give the recommended tightening torques for general purpose metric and UNC fasteners. They are to be
used only when the joint is metal to metal (i.e. no joints or gaskets) and no special figures (e.g. for impeller retaining bolts) have
been quoted.
Table 2 Metric
Fasteners
Steel
Stainless
Torque (N-m)
Thread Size
Nuts & Bolts
Nuts on Studs
All
M6 x 1.0 11.7 4.6 9
M8 x 1.25 28 11 22
M10 x 1.5 56 22 44
M12 x 1.75 98 38 76
M16 x 2.0 244 95 187
M20 x 2.5 476 185 364
M24 x 3.0 822 320 629
M30 x 3.5 1633 633 1240
Table 3 UNC
Fasteners
Steel
Stainless
Torque (N-m)
Thread Size
Nuts & Bolts
Nuts on Studs
All
¼” - 20 13.5 5.4 10.5
5/16” – 18 27.1 10.5 21.0
3/8” – 16 48.8 20 37.8
7/16” – 14 74.6 30 57.8
½” – 13 122 48 94.6
5/8” – 11 237.3 95 183.9
¾” – 10 420.4 167 325.8
7/8” – 9 664.4 266 514.9
1” - 8 1003 401 777.3
Table 1 figures are for Metric fasteners to BS3692. Steel fasteners: - Grade 8.8 for bolts, Grade 4.6 for studs, Grade 10 for nuts;
Stainless Steel fasteners: - Grade A2 or A4, Class 70 or 80.
Table 2 figures are for UNC fasteners to BS1768 Steel fasteners: -Grade S and Grade 3 for nuts; Stainless Steel fasteners: -
Grade A2.
If steel fasteners are of dissimilar condition then the figures Table 1 or Table 2 must be multiplied by those in Table 3.
Table 4 Correction factors
PLATING CONDITION OF BOLT
BLACK ZINC
PLATING CONDITION OF
NUT
BLACK
1.0
0.9
ZINC
0.9
0.8