ENSTROM F-28F/280F SERIES MAINTENANCE MANUAL
Rev.
6
MM-2-17
Apr
7/15
Table 2-5. Torque Values for Nuts and Bolts
CAUTION THE FOLLOWING TORQUE VALUES ARE DERIVED FROM OIL FREE CADMIUM PLATED THREADS.
TORQUE LIMITS RECOMMENDED FOR INSTAL-
LATION (BOLTS LOADED PRIMARILY IN SHEAR)
(inch-pounds)
MAXIMUM ALLOWABLE TIGHTENING
TORQUE LIMITS
(inch-pounds)
Thread Size
Tension type nuts
MS20365 and AN310
(40,000 psi in bolts)
Shear type nuts MS20364
and AN320 (24,000 psi in
bolts)
Nuts MS20365 and
AN310 (90,000 psi in
bolts)
Nuts MS20364 and
AN320 (54,000 psi in
bolts)
FINE THREAD SERIES
8-36
12-15
7-9
20
12
10-32
20-25
12-15
40
25
1/4-28
50-70
30-40
100
60
5/16-24
100-140
60-85
225
140
3/8-24
160-190
95-110
390
240
7/16-20
450-500
270-300
840
500
1/2-20
480-690
290-410
1100
660
9/16-18
800-1000
480-600
1600
960
5/8-18
1100-1300
600-780
2400
1400
3/4-16
2300-2500
1300-1500
5000
3000
7/8-14
2500-3000
1500-1800
7000
4200
1-14
3700-5500
2200-3300*
10,000
6000
1-1/8-12
5000-7000
3000-4200*
15,000
9000
1-1/4-12
9000-11,000
5400-6600*
25,000
15,000
COARSE THREAD SERIES
8-32
12-15
7-9
20
12
10-24
20-25
12-15
35
21
1/4-20
40-50
25-30
75
45
5/16-18
80-90
48-55
160
100
3/8-16
160-185
95-100
275
170
7/16-14
235-255
140-155
475
280
1/2-13
400-480
240-290
880
520
9/16-12
500-700
300-420
1100
650
5/8-11
700-900
420-540
1500
900
3/4-10
1150-1600
700-950
2500
1500
7/8-9
2200-3000
1300-1800
4600
2700
The above torque values may be used for all cadmium-plated steel nuts of the fine or coarse thread series which have
approximately equal number of threads and equal face bearing areas. * Estimated corresponding values.
Table 2-6. Fittings, Tubing
Fitting
Size
Tubing OD
(inches)
6061-O & 5052-O Aluminum-
Alloy Tube: Fitting or Nut
Torque (in-lb)
Steel Tube:
Fitting or Nut Torque
(in-lb)
-2
1/8
20-30
75-85
-3
3/16
25-35
95-105
-4
1/4
50-65
135-150
-5
5/16
70-90
170-200
-6
3/8
110-130
270-300
-8
1/2
230-260
450-500
-10
5/8
330-360
650-700
-12
3/4
460-500
900-1000
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