Hitachi Koki WH14DM Manual De Instrucciones página 19

4. Use a tightening time suitable for the screw
The appropriate torque for a screw differs according to the material and size of the
screw, and the material being screwed etc., so please use a tightening time suitable for
the screw. In particular, if a long tightening time is used in the case of screws smaller
than 5/16" (8 mm), there is a danger of the screw breaking, so please confirm the
tightening time and the tightening torque beforehand.
3/8"×1-3/6"
kgf•cm N•m (M10×30)
(in-lbs)
160
1600
(1390)
140
1400
High strenge bolt
(1218)
120
1200
(1042)
100
1000
(868)
80
800
(695)
Ordinary bolt
60
600
(521)
40
400
(347)
20
200
(174)
0
0
0 1
Tightening time: sec
(Steel plate thickness
t = 3/8" (10 mm))
Bolt
Steel plate
thickness t
Nut
kgf•cm N•m
(in-lbs)
160
1600
(1390)
140
1400
(1218)
120
1200
(1042)
100
1000
(868)
80
800
(695)
60
600
(521)
40
400
(347)
20
200
(174)
0
2 3
Tightening time: sec
(Steel plate thickness
t = 1" (25 mm))
*The following bolt is used.
Ordinary bolt: Strength grade 4.8
High tensile bolt: Hardness division 12.9
(
Explanation of strength grade:
4 — Yield point of bolt: 45,500 psi (32 kgf/mm
8 — Pulling strength of bolt: 56,900 psi (40 kgf/mm
15/32"×1-3/4"
(M12×45)
High strenge bolt
Ordinary bolt
0
0 1 2 3
Fig. 15
Fig. 16
9/16"×1-31/32"
kgf•cm N•m
(M14×50)
(in-lbs)
160
1600
High strenge bolt
(1390)
140
1400
(1218)
120
1200
(1042)
100
1000
(868)
Ordinary bolt
80
800
(695)
60
600
(521)
40
400
(347)
20
200
(174)
0
0
0 1
Tightening time: sec
(Steel plate thickness
t = 1" (25 mm))
2 )
English
2 3
)
2 )
19