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Tightening torque
Tightening time (Sec.)
M16, M20, M24 x 45 mm
High tensile bolt
Bolt
Nut
Washer
Steel plate
thickness 10 mm
Washer
Spring washer
Tightening conditions
• The following bolts are used.
Standard bolts: Strength type 4.8
High tensile type 12.9
4.8
Explanation of the strength type
Bolt yield point
(80% of tensile strength)
32 kgf/mm2 (45000 psi)
Bolt tensile strength
40 kgf/mm2 (56000 psi)
2) Tightening time
Longer tightening time results in increased
tightening torque. Excessive tightening,
how ever, adds no value and reduces the
life of the tool.
3) Different bolt diameters
The size of the bolt diameter affects the
tight ening torque.
Generally, as the bolt diameter increases,
tightening torque rises.
4) Tightening conditions
• Tightening torque will vary, even with the
same bolt, according to grade, length, and
torque coefficient (the fixed coefficient indi-
cated by the manufacturer upon produc-
tion).
VI. MAINTENANCE
• Use only a dry, soft cloth for wiping the unit.
Do not use a damp cloth, thinner, benzine, or
other volatile solvents for cleaning.
• In the event that the inside of the tool or
battery pack is exposed to water, drain and
allow to dry as soon as possible. Carefully
remove any dust or iron filings that collect
inside the tool. If you experience any
problems operating the tool, consult with a
repair shop.
VII. TIGHTENING TORQUEThe power required for tightening a bolt will
vary, according to bolt material and size, as
well as the material being bolted. Choose
the length of tightening time accordingly.
Reference values are provided below.
(They may vary according to tightening
conditions.)
Factors Affecting Tighten-
ing Torque
The tightening torque is affected by a wide
variety of factors including the followings.
After tightening, always check the torque
with a torque wrench.
1) Voltage
When the battery pack becomes nearly
discharged, the voltage decreases and the
tightening torque drops.
M16, M20, M24 x 45 mm
Standard bolt
Tightening torque
Tightening time (Sec.)