Panasonic EY7542 Operating Instructions Manual page 18

Bolt
Nut
Tightening conditions
• The following bolts are used.
Standard bolts: Strength type 4.8
High tensile type 12.9
Explanation of the strength type
4.8
Bolt yield point
(80% of tensile strength)
32 kgf/mm
Bolt tensile strength
40 kgf/mm
2) Tightening time
Longer tightening time results in in-
creased 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 in-
creases, 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).
Tightening torque will vary, even with
the same bolting material (e.g. steel),
accord ing to the surface finish.
Torque is greatly reduced when the
bolt and nut start turning together.
5) Socket play
Torque is lowered as the six-sid-
ed configu ration of the socket of the
wrong size is used to tighten a bolt.
6) Switch (Variable speed control trigger)
Torque is lowered if the unit is used
with the switch not fully depressed.
7) Effect of Connecting Adapter
The tightening torque will be lowered
through the use of a universal joint or
a socket adapter.
EY7542(EU).indb 18
Washer
Steel plate
thickness10 mm (3/8")
Washer
Spring washer
2 (45000psi)
2 (56000psi)
- 18 -
• Universal joint
• Socket adapter
2012-10-12 15:38:34