NPK GH7 - Torque Values for Hammer Fasteners; Socket Head Cap Screws (SHCS); Hex Head Bolts

NPK
- 55 -
TORQUE VALUES FOR HAMMER FASTENERS
If hammer or hammer bracket fasteners are found to be loose, use the following charts.
Medium strength thread adhesive should be used on all the valve assembly bolts and
the gas charge valve. All other bolts should be lubed with anti-seize compound.

SOCKET HEAD CAP SCREWS (SHCS)
MODEL
VALVE CASE
VALVE TOP AND
BOTTOM CAP
SWIVEL ADAPTER
SHCS
DIA
TORQUE
ft/lb (Nm)
SHCS
DIA
TORQUE
ft/lb (Nm)
SHCS
DIA
TORQUE
ft/lb (Nm)
GH7 M20 425 (580) M18 290 (395) M12 85 (115)
GH9 M24 600 (810) M22 495 (670) M12 85 (115)
GH10 M24 600 (810) M22 495 (670) M12 85 (115)
GH12 M24 600 (810) M22 495 (670) M12 85 (115)
GH15 M27 925 (1250) M24 600 (810) M14 145 (200)
GH18 M27 925 (1250) M24 600 (810) M14 145 (200)
GH23 M27 925 (1250) M24 600 (810) M14 145 (200)
GH30 M27 925 (1250) M27 925 (1250) M14 145 (200)
GH40 M27 925 (1250) M27 925 (1250) M16 155 (210)
GH50 M30 1400 (1900) M30 1400 (1900) M16 155 (210)
See HAMMER DISASSEMBLY AND ASSEMBLY – TOOLS AND EQUIPMENT section
of the Service Manual for NPK hex key wrench part numbers.
HEX HEAD BOLTS
MODEL
HAMMER BRACKET RUBBER MOUNTS
TOP ADAPTER
BRACKET
BOLT
DIA
TORQUE
ft/lb (Nm)
BOLT
DIA
TORQUE
ft/lb (Nm)
BOLT
DIA
TORQUE
ft/lb (Nm)
GH7
See Next Page For Bolt
Torques
M16 155 (210) 1” 750 (1015)
GH9 M16 155 (210) 1” 750 (1015)
GH10 M20 300 (405) 1” 750 (1015)
GH12 M20 300 (405) 1-1/4” 1500 (2030)
GH15 M20 300 (405) 1-1/4” 1500 (2030)
GH18 M20 300 (405) 1-1/4” 1500 (2030)
GH23 M24 530 (720) 1-1/4” 1500 (2030)
GH30 M24 530 (720) 1-1/4” 1500 (2030)
GH40 M24 530 (720) 1-1/4” 1500 (2030)
GH50 M24 530 (720) 1-3/8” 2000 (2710)