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UTD.123.2019-10.00_EN
7.4 - Tightening torques for fastening bolts (feet, flange, accessories) and for plugs
Unless otherwise stated, usually it is sufficient to use screws in class 8.8;
Before tightening the bolt be sure that the eventual centering of flanges are inserted properly- Before
tightening the bolt be sure that the eventual centering of flanges are inserted properly
The bolts are to be diagonally tightened with the maximum tightening torque.
Before tightening, carefully degrease the screws; in the event of heavy vibrations, heavy duties, frequent
drive inversions apply a proper thread-locking sealant Loxeal 23-18 or equivalent.
Pay attention to 12.9 bolts tightening. Values higher than recommended values can damage the bolts.
Do not use lubricants altering the friction coefficient for they may overload the screw connection.
Always verify the tightening torque after the first hours of running.
A, E, G, H series
Tab. 7.4.2 - Tightening torque for plugs
Gear red.
size
Thread
dimension
M
S
[N m]
40, 50
G 1/4’’
7
63 ... 81
M16
×
1,5
14
100 ... 140
G 1/2’’
14
160 ... 280
G 3/4’’
14
320 ... 360
G 1’’
25
400, 401
G 1’’
25
4001... 6301
G 1’’
25
7101
G 1’’1/4
25
8001
G 1’’1/2
25
Tab. 7.4.1 - Tightening torque for fastening bolts, feet and flanges
Screw
M
S
[N m]
UNI 5737-88, UNI 5931-84
cl. 8.8
cl 10.9
cl. 12.9
M4
2.9
4
–
M5
6
8.5
10
M6
11
15
20
M8
25
35
40
M10
50
70
85
M12
85
120
145
M14
135
190
230
M16
205
290
350
M18
280
400
480
M20
400
560
680
M22
550
770
930
M24
710
1 000
1 200
M27
1 000
1 400
1 700
M30
1 380
1 950
2 350
M33
2 000
2 800
3 400
M36
2 500
3 550
4 200
M39
2 950
4 200
5 000
M42
4 100
5 800
6 900
M45
5 000
7 100
8 400
M48
6 100
8 600
10 300
M56
9 800
13 800
16 500
Filler plugs
Plug with breather
Ø
Ch
Tightening torque
Ø
Ch
Tightening torque
(with aluminium washer)
[Nm]
[Nm]
G 1/8 "
5
8
G 1/4 "
17
12
G 1/4"
6
13
G 3/8 "
20
16
G 3/8 "
8
20
G 1/2 "
24
23
G 1/2 "
10
30
G 3/4 "
32
37
G 3/4"
12
45
G 1"
40
58
G 1"
17
65
G 1" 1/4
50
105
G 1" 1/4
22
100
G 1" 1/2
55
126
G 1" 1/2
24
125
EP series
Plugs
For the size of plugs and breather plug and the value of tightening torque see table below.
Table 8.3.2