
Torque Tables And Conversion Charts - Section 12 02/11 OM1200
Page 12-2
EFFECT OF SPECIAL LUBRICANTS
On Fasteners and Standard Torque Values
The Komatsu engineering department does not
recommend the use of special friction-reducing
lubricants, such as Copper Coat, Never-Seez®, and
other similar products, on the threads of standard
fasteners where standard torque values are applied.
The use of special friction-reducing lubricants will
significantly alter the clamping force being applied to
fasteners during the tightening process.
If special friction-reducing lubricants are used with
the standard torque values listed in this chapter,
excessive stress and possible breakage of the
fasteners may result.
Where the torque tables specify “Lubricated
Threads” for the standard torque values listed, these
standard torque values are to be used with simple
lithium base chassis grease (multi-purpose EP NLGI)
or a rust-preventive grease (see below) on the
threads and seats unless specified otherwise.
NOTE: Ensure the threads of fasteners and tapped
holes are free of burrs and other imperfections before
assembling.
Suggested* Sources for Rust Preventive Grease:
• American Anti-Rust Grease #3-X from Standard
Oil Company (also American Oil Co.)
• Gulf NoRust #3 from Gulf Oil Company.
• Mobilarma 355, Product No. 66705 from Mobil
Oil Corporation.
• Rust Ban 326 from Humble Oil Company.
• Rustolene B Grease from Sinclair Oil Co.
• Rust Preventive Grease - Code 312 from the
Southwest Grease and Oil Company.
NOTE: This list represents the current engineering
approved sources for use in Komatsu manufacture. It
is not exclusive. Other products may meet the same
specifications of this list.
STANDARD TIGHTENING TORQUES
For Class 10.9 Cap screws & Class 10 Nuts
The following specifications apply to required
assembly torques for all metric class 10.9 finished
hexagon head cap screws and class 10 nuts.
• Cap screw threads and seats shall not be
lubricated when assembled. These specifications
are based on all cap screws, nuts, and hardened
washers being phosphate and oil coated.
If zinc-plated hardware is used, each piece must
be lubricated with simple lithium base chassis
grease (multi-purpose EP NLGI) or a rust
preventive grease (see list, this page) to achieve
the same clamping forces provided below.
• Torques are calculated to give a clamping force
of approximately 75% of proof load.
• The maximum torque tolerance shall be within
±10% of the torque value shown.
• In the following table under “Cap Screw Size”, the
first number represents the shank diameter
(mm). The second number represents threads
per millimeter.
Example: M20 x 2.25
M20 = shank diameter (20 mm)
2.25 = thread pitch in millimeters
TABLE 1.
Standard Tightening Torque
for Metric Class 10.9 Cap screws & Class 10 Nuts
Cap Screw
Size Torque
N•m Torque
ft lb Torque
kg•m
M6 x1 12 9 1.22
M8 x 1.25 30 22 3.06
M10 x 1.5 55 40 5.61
M12 x 1.75 95 70 9.69
M14 x 2 155 114 15.81
M16 x 2 240 177 24.48
M20 x 2.25 465 343 47.43
M24 x 3 800 590 81.6
M30 x 3.5 1600 1180 163.2
M36 x 4 2750 2028 280.5