User Manual

Manual No/Rev
W12-005E / 3
Operators Instructions for Horizontal
Extended Thrustream Centrifugal Pumps
Our policy is one of continuous improvement and we reserve the right to alter specifications at any time
Page 24 of 28
9. Standard Metric Nut and Bolt Torque Recommendations
This information is for reference only. The user must check that the torque figures listed here are applicable to
the fasteners used. Nuts and bolts should be neither under nor over tightened.
Grade of Bolt
Approximate Torque (Nm) for Bolt Diameters:
M5
M6
M8
M10
M12
M16
M20
M24
M30
M36
4.6
2.7 4.5 11 22 38 95 185 320 633 1110
8.8
6.9 11.7 28 56 98 244 476 822 1634 2855
10.9
9.4 15.9 38 77 134 332 646 1120 2223 3885
12.9
11.2 19.1 46.4 92 160 397 775 1342 2666 4660
Note: These torque figures are approximate, and for un-plated fasteners only. No allowance has been made for
special finishes or lubricants, washers or mating surfaces.
Bolt and Nut Grade Combinations
Grade of BOLT
4.6 8.8 10.9 12.9
Note: It is permissible to fit higher grade
nuts than recommended.
Grade of NUT
4 8 12 12
Grade Identification
BOLTS & NUTS - Grade 4.6
BS4190 (ISO272, 885, 888 & 4759/1). Grade marking is optional.
Normally there will be no mark other than the 'M' thus:
BOLTS - Grade 8.8
BS 3692 (ISO272, 4759/1). Grade
marking is mandatory, may also
have trade marks
NUTS - Grade 8
Indented marks as a clock face,
dot at 12.00, bar at 8.00,
indicates grade 8 nut.
High Strength Friction Grip Bolts & Nuts
BOLT NUT BOLT
Grade10.9
NUT
Grade 12