Panasonic EY6535 - Understanding Tightening Torque; Factors Affecting Tightening Torque; Bolt Tightening Conditions

—
12
—
TIGHTENING TORQUE
• The 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 TIGHTENING 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.
Bolt Tightening Conditions
M6, M8, M10, M12, M14 x 25 mm (1") Standard bolt
(Bolt size : Millimeters)
1300
(1100)
kgf-cm
(in-lbs)
M14
400
(350)
600
(500)
800
(700)
1000
(850)
0.1 0.25 0.5
Tightening time (Sec.)
123
1200
(1000)
Tightening torque
200
(170)
M8
M6
M10
M12
Washer
Washer
Spring washer
Steel plate
thickness 10 mm (3/8")
Bolt
Nut
Tightening conditions
*The following bolts are used.
Standard bolt: Strength type 4.8
High tensile type 12.9
Explanation of the strength type
4.8
Bolt tensile strength 60 kgf/mm
2
(85,000psi)
Bolt yield point
(80% of tensile strength)
48 kgf/mm
2
(68,000psi)
EY6535.book 12