NPK GH2 - TORQUE VALUES FOR HAMMER FASTENERS

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TORQUE VALUES FOR HAMMER FASTENERS
If hammer or hammer bracket fasteners are found to be loose, use the following charts.
If repairs are to be made, see the NPK Hydraulic Hammer Service Manual.
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.
VALVE CASE
VALVE TOP AND
BOTTOM CAP
SWIVEL ADAPTER
MODEL
BOLT
DIA
TORQUE
ft/lb (Nm)
BOLT
DIA
TORQUE
ft/lb (Nm)
BOLT
DIA
TORQUE
ft/lb (Nm)
GH06 M12 110 (150) M10 65 (85) N/A N/A
GH07 M12 110 (150) M10 65 (85) N/A N/A
GH1 M12 110 (150) M10 65 (85) N/A N/A
GH2 / GHS2 M12 110 (150) M12 110 (150) N/A N/A
GH3 M16 270 (365) M16 270 (365) M8 30 (40)
GH4 M18 370 (500) M16 270 (365) M8 30 (40)
GH6 M20 525 (710) M18 370 (500) M12 110 (150)
*NOTE: TORQUES OF ALL BOLTS SHOWN ARE WITH THREADS BEING
LUBRICATED.
HEX SOCKET SIZE
BOLT DIAMETER SOCKET HEAD CAP SCREW
M10 8mm
M12 10mm
M14 12mm
M16 14mm
M18 14mm
MODEL
HAMMER BRACKET ADAPTER BRACKET
BOLT
DIA
TORQUE
ft/lb (Nm)
BOLT
DIA
TORQUE
ft/lb (Nm)
GH06 1" 500 (678) 5/8” 165 (225)
GH07 1" 500 (678) 5/8” 165 (225)
GH1 1” 500 (678) 5/8” 165 (225)
GH2 / GHS2 1” 500 (678) 5/8” 165 (225)
GH3 1-1/4” 1000 (1356) 5/8” 165 (225)
GH4 1-1/2” 1250 (1695) 5/8” 165 (225)
GH6 1-1/2” 1250 (1695) 1” 550 (745)