MB ZTS - Fastener Torque Recommendations; Standard Fastener Torque Values

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Publication: ZTS-080812
M-B Companies, Inc. 11/15/12
INTRODUCTIONFASTENER TORQUE RECOMMENDATION
TORQUE FOR STANDARD FASTENERS
Nominal
Dia.
Threads
per inch
Tightening Torque Tightening Torque Tightening Torque Tightening Torque
Lubed
Dry
Plated
Dry
Plain
Lubed
Dry
Plated
Dry
Plain
Lubed
Dry
Plated
Dry
Plain
Lubed
Dry
Plated
Dry
Plain
(in.) K = 0.15 K = 0.17 K = 0.20 K = 0.15 K = 0.17 K = 0.20 K = 0.15 K = 0.17 K = 0.20 K = 0.15 K = 0.17 K = 0.20
Unified Coarse Thread Series
1/4 20 49 in-lbs 59 in-lbs 66 in-lbs 76 in-lbs 86 in-lbs 101 in-lbs 107 in-lbs 122 in-lbs 143 in-lbs 126 in-lbs 143 in-lbs 168 in-lbs
5/16 18 101 122 135 157 178 209 221 251 295 259 294 346
3/8 16 15 ft-lbs 18 ft-lbs 20 ft-lbs 23 ft-lbs 26 ft-lbs 31 ft-lbs 33 ft-lbs 37 ft-lbs 44 ft-lbs 38 ft-lbs 43 ft-lbs 51 ft-lbs
7/16 14 24 29 32 37 42 49 52 59 70 61 70 82
1/2 13 37 44 49 57 64 75 80 90 106 94 106 125
9/16 12 53 63 70 82 92 109 115 130 154 135 153 180
5/8 11 73 87 97 113 126 150 159 180 212 186 211 248
3/4 10 129 155 172 200 227 267 282 320 376 331 375 441
7/8 9 125 160 167 322 365 429 455 615 606 633 604 710
1 8 187 225 250 483 547 644 681 722 909 799 905 1065
1-1/8 7 266 319 354 596 675 794 966 1095 1288 1132 1283 1510
1-1/4 7 375 450 500 840 952 1121 1363 1545 1817 1597 1810 2130
1-1/2 6 652 783 869 1462 4657 1950 2371 2688 3162 2779 3150 3706
Fine Thread Series
1/4 28 56 in-lbs 68 in-lbs 75 in-lbs 87 in-lbs 99 in-lbs 116 in-lbs 123 in-lbs 139 in-lbs 164 in-lbs 144 in-lbs 163 in-lbs 192 in-lbs
5/16
24 112 135 150 174 197 231 245 278 327 287 325 383
3/8 24 17 ft-lbs 20 ft-lbs 23 ft-lbs 26 ft-lbs 30 ft-lbs 35 ft-lbs 37 ft-lbs 42 ft-lbs 49 ft-lbs 43 ft-lbs 49 ft-lbs 58 ft-lbs
7/16 20 27 32 36 41 47 55 58 66 78 68 78 91
1/2 20 41 49 55 64 72 85 90 102 120 105 120 141
9/16 18 59 71 78 91 103 121 126 146 171 151 171 201
5/8 18 82 99 110 127 144 170 180 204 240 211 239 281
3/4 16 144 173 192 223 253 297 315 357 420 369 418 492
7/8 14 138 165 184 355 403 474 502 568 669 588 666 784
1 14 210 252 280 542 614 722 765 867 1020 896 1016 1195
1-1/8 12 298 357 397 668 757 890 1083 1227 1444 1269 1439 1693
1-1/4 12 415 493 553 930 1055 1241 1509 1710 2012 1768 2004 2358
1-1/2 12 734 880 978 1645 1865 2194 2668 3024 3557 3127 3544 4169
Torque values for 1/4 and 5/16-in series are in inch -pounds. All other torque values are in foot-pounds
Torque values calculated from formulas T=KDF, where
K = 0.15 for “lubricated” conditions
K = 0.17 for zinc plated and dry conditions
K = 0.20 for plain and dry conditions
D = Nominal Diameter
F = Clamp Load
Grade 2 Grade 5 Grade 8
F
N
L
G
9
Grade 9