--- 24 ---
Tightening time: sec.
(Steel plate thickness
t = 10 mm)
200
0
1
2
3
400
600
800
1000
kgf
•
cm
M10 x 30
Tightening torque
High-strength bolt
0
0
20
40
60
80
100
N
•
m
Tightening time: sec.
(Steel plate thickness
t = 25 mm)
0
1
2
3
Tightening time: sec.
(Steel plate thickness
t = 25 mm))
M14 x 50
High-strength bolt
Ordinary bolt
Tightening torque
200
0
1
2
3
400
600
800
1000
kgf
•
cm
M12 x 45
Tightening torque
High-strength bolt
0
0
20
40
60
80
100
N
•
m
Ordinary bolt
Ordinary bolt
120
140
1200
1400
200
400
600
800
1000
kgf
•
cm
0
0
20
40
60
80
100
N
•
m
120
140
1200
1400
•
Model WH 12DM2
7-3-3. Bolt tightening torque characteristics
Figures. 6-1 and 6-2 show relationships between time and tightening torque for individual bolt types and sizes.
While the data are useful for handy reference, actual tightening torque will vary depending on tightening
conditions and other variables. For details, please refer to Para. 8-3, "Tightening Torque Variation".
(Note)
•
The term "tightening time" indicates the impact time after the lower surface of the bolt has come in contact with
the material into which it is being tightened.
•
In the tightening conditions shown in Figs. 6-1 and 6-2, the screws are being tightened directly into a steel
plate; accordingly, the torque goes up very abruptly in comparison with ordinary bolt tightening conditions.
Fig. 6-2
Bolt
Nut
Steel plate
thickness: t
* The following bolts were utilized:
Ordinary bolt; strength grade 4.8
High-strength bolt; strengh grade
12.9
Strength grade is read as follows:
4.8
Yield point or durable force:
(45,500 psi)
Tensile strength of the bolt:
(56,900 psi)
•
Model WR 12DM2
Tightening time: sec.
(Steel plate thickness
t = 10 mm)
500
0
1
2
3
1000
1500
2000
kgf
•
cm
M10 x 30
Tightening torque
High-strength bolt
0
0
50
100
150
200
N
•
m
Ordinary bolt
Tightening time: sec.
(Steel plate thickness
t = 25 mm)
500
0
1
2
3
1000
1500
2000
kgf
•
cm
M12 x 45
Tightening torque
High-strength bolt
0
0
50
100
150
200
N
•
m
Ordinary bolt
Tightening time: sec.
(Steel plate thickness
t = 25 mm)
500
0
1
2
3
1000
1500
2000
kgf
•
cm
M14 x 50
Tightening torque
High-strength bolt
0
0
50
100
150
200
N
•
m
Ordinary bolt
Fig. 6-1
