Flange Bolting Torque Table 1A

The torque tables are built on specific assumptions regarding bolt and nut factor. Before using a given torque table, these assumptions should be verified to insure they are appropriate for the specific application.

Even if all assumptions are appropriate, results may vary depending on actual conditions. Many factors induce scatter in the results or increase the inherent variability in the bolting process. These include variations in the nut factor; bolt, flange and nut condition; equipment calibration and condition; perpendicularity of the bolt, nut and flange; etc.


The values in the tables are based on the equation..


Bolting Torque T = Torque value, (ft-lbs)
F = Bolt pre-load, (lbs)
k = Nut Factor based on lubricant used
d = Nominal bolt diameter, (in.)
Hydraulic Torque Wrench

The nut factor is not the coefficient of friction.
It is an experimentally derived constant that includes the impact of friction.


ft-lbs to nm = 0.737562149277
nm to ft-lbs = 1.3558179


Table 1A / Torque FT-LBS - Cold Service ASTM A193 and ASTM A320 Grade B8, CL2 Stud Bolts
BOLT
DIA
Torque Ft*lb
30% Initial
Torque
70%
Torque
100% Final
Torque
1/2 22 51 73
9/16 32 74 105
5/8 44 102 145
3/4 77 180 257
7/8 100 232 332
1 149 348 498
1.1/8 178 415 593
1.1/4 250 584 834
1.3/8 261 609 870
1.1/2 345 804 1149
1.9/16 235 549 784
1.5/8 267 624 891
1.3/4 336 785 1121
1.7/8 418 974 1392
2 512 1194 1706
2.1/4 740 1727 2467
2.1/2 1026 2393 3419
2.3/4 1380 3219 4599
3 1805 4211 6015

Table 1A / Torque Nm - Cold Service ASTM A193 and ASTM A320 Grade B8, CL2 Stud Bolts
BOLT
DIA
Torque N*m
30% Initial
Torque
70%
Torque
100% Final
Torque
1/2 30 69 99
9/16 43 100 142
5/8 60 138 197
3/4 104 244 348
7/8 136 315 450
1 202 472 675
1.1/8 241 563 804
1.1/4 339 792 1131
1.3/8 354 826 1180
1.1/2 468 1090 1558
1.9/16 319 744 1063
1.5/8 362 846 1208
1.3/4 456 1064 1520
1.7/8 567 1321 1887
2 694 1619 2313
2.1/4 1003 2341 3345
2.1/2 1391 3244 4636
2.3/4 1871 4364 6235
3 2447 5709 8155

Notes..

  • Bolting torque to develop 70% Bolt Yield Stress at Nut Factor, K=0.16
  • This Table is applicable to Never-Seize paste and Fel-Pro lubricant, K=0.16.
  • The above Table is applicable only for ASTM A320 Grade B8, Class 2 and A193 Grade B8, Class 2 Stud Bolts. These are 304 SS material.
  • The torque values are approved for spiral wound graphite and PTFE filled gaskets.
  • The Final Torque Value accounts for 10% bolt relaxation.
  • The yield strength for strain-hardened bolts varies with diameter. Torque values for bolts greater than 1.1/2 in. diameter are based on 30 ksi yield strength.

OTHER BOLTING TORQUE TABLES

BOLTING TORQUE TABLE 1 - ASTM A193 AND ASTM A320 GRADE B8, CL2 STUD BOLTS

BOLTING TORQUE TABLE 1A - COLD SERVICE ASTM A193 AND ASTM A320 GRADE B8, CL2 STUD BOLTS

BOLTING TORQUE TABLE 2 - ASTM 193 GRADE B7 AND ASTM 193 GRADE B16 STUD BOLTS

BOLTING TORQUE TABLE 2A - COLD SERVICE ASTM A320 GRADE L7 STUD BOLTS

BOLTING TORQUE TABLE 3 - USE ONLY WITH A193 B8, CL1 BOLTS AT 540°C - 650°C ON UNINSULATED FLANGES

BOLTING TORQUE TABLE 4 - USE ONLY WITH 6061-T6 ALUMINIUM FLANGES

BOLTING TORQUE TABLE 5 - PTFE COATED ASTM A193 B7 and ASTM 193 B16 STUD BOLTS

BOLTING TORQUE TABLE 5A - COLD SERVICE PTFE COATED ASTM A320 GRADE L7 STUD BOLTS

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