Guide 08 · Fastener Reference Guide
Recommended Assembly Torques
The torques listed are for plain finish (uncoated) fasteners as supplied.
Torque is not the goal. Bolt tension is. Torque is simply the most convenient way to estimate it, and it is a rough estimate — most of the effort you apply goes into overcoming friction under the nut face and in the threads, not into stretching the bolt.
That is why the figures below are stated for plain finish, uncoated fasteners as supplied. Change the condition of the joint and the same torque delivers a different tension:
- Lubricant, anti-seize or a fresh coating lowers friction, so the same torque produces significantly more tension — enough to yield the bolt.
- A galvanised, dirty, damaged or reused thread raises friction, so the same torque produces less tension than intended.
The practical consequences are worth spelling out. Do not apply a plain-finish torque figure to a lubricated bolt. Do not swap in an impact wrench and assume the result matches a torque wrench. And where a connection is specified as fully tensioned (8.8/TF or 8.8/TB), torque is not the accepted method at all — use part-turn, load-indicating washers or a calibrated tool as the standard requires.
Where the tension actually matters, confirm the figure against the relevant standard or your engineer's specification rather than a general table.
Text version — searchable and screen-reader friendly
Recommended Assembly Torques – BSW BSW Low Tensile Bolts AS/NZS 2451
| Diameter & Thread | Diameter & Thread | Induced Bolt Preload or Tension Corresponding to 65% of Yield Load (lbf) | Recommended Assembly Torque to Give induced Preload Equal to 65% of Yield Load (lbft) |
|---|---|---|---|
| 1/4 | BSW | 750 | 3 |
| 5/16 | BSW | 1230 | 6 |
| 3/8 | BSW | 1820 | 12 |
| 7/16 | BSW | 2480 | 19 |
| 1/2 | BSW | 3250 | 28 |
| 5/8 | BSW | 5300 | 55 |
| 3/4 | BSW | 7830 | 98 |
| 7/8 | BSW | 10200 | 150 |
| 1 | BSW | 13300 | 230 |
| 1.1/8 | BSW | 16700 | 320 |
| 1.1/4 | BSW | 21500 | 450 |
| 1.1/2 | BSW | 30800 | 780 |
Class 4.6 Property Class 4.6 Commercial Low Tensile Bolts
| Diameter (mm) | Bolt Tension Corresponding to 65% of Proof Load (kN) | Bolt Tension Corresponding to 65% of Proof Load (lbf) | Recommended Assembly Torque (Nm) | Recommended Assembly Torque (lbft) |
|---|---|---|---|---|
| 5 | 2.08 | 468 | 2.1 | 1.5 |
| 6 | 2.94 | 660 | 3.5 | 2.5 |
| 8 | 5.34 | 1200 | 8.5 | 6.3 |
| 10 | 8.45 | 1900 | 17 | 12 |
| 12 | 12.4 | 2790 | 30 | 22 |
| 14 | 16.8 | 3780 | 47 | 35 |
| 16 | 22.9 | 5150 | 73 | 54 |
| 18 | 28.1 | 6320 | 101 | 75 |
| 20 | 35.8 | 8050 | 143 | 106 |
| 22 | 44.3 | 9960 | 195 | 145 |
| 24 | 51.6 | 11600 | 248 | 183 |
| 27 | 67 | 15060 | 362 | 265 |
| 30 | 81.9 | 18410 | 491 | 362 |
| 33 | 101 | 22800 | 669 | 495 |
| 36 | 120 | 26980 | 864 | 637 |
| 39 | 143 | 32150 | 1115 | 820 |
| 42 | 164 | 36870 | 1378 | 1020 |
| 48 | 215 | 48330 | 2064 | 1520 |
| 56 | 298 | 66990 | 3338 | 2460 |
| 64 | 393 | 88350 | 5030 | 3710 |
Recommended Assembly Torques – Grade 5 Grade 5 Unified High Tensile Bolts (Same as SAE J429 Grade 5) AS/NZS 2465
| Diameter & Thread | Diameter & Thread | Induced Bolt Preload or Tension Corresponding to 65% of Yield Load (lbf) | Recommended Assembly Torque to Give induced Preload Equal to 65% of Yield Load (lbft) |
|---|---|---|---|
| 1/4 | UNF | 2020 | 8 |
| 5/16 | UNF | 3190 | 17 |
| 3/8 | UNF | 4840 | 30 |
| 7/16 | UNF | 6570 | 48 |
| 1/2 | UNF | 8840 | 74 |
| 5/8 | UNF | 14170 | 150 |
| 3/4 | UNF | 20610 | 260 |
| 7/8 | UNF | 28150 | 410 |
| 1 | UNF | 36660 | 610 |
| 1/4 | UNC | 1760 | 7 |
| 5/16 | UNC | 2890 | 15 |
| 3/8 | UNC | 4290 | 27 |
| 7/16 | UNC | 5880 | 43 |
| 1/2 | UNC | 7870 | 66 |
| 5/8 | UNC | 12480 | 130 |
| 3/4 | UNC | 18400 | 230 |
| 7/8 | UNC | 25550 | 370 |
| 1 | UNC | 33480 | 560 |
Recommended Assembly Torques – Grade 8 Grade 8 Unified High Tensile Bolts (Same as SAE J429 Grade 8) AS/NZS 2465
| Diameter & Thread | Diameter & Thread | Induced Bolt Preload or Tension Corresponding to 65% of Yield Load (lbf) | Recommended Assembly Torque to Give induced Preload Equal to 65% of Yield Load (lbft) |
|---|---|---|---|
| 1/4 | UNF | 2830 | 12 |
| 5/16 | UNF | 4520 | 23 |
| 3/8 | UNF | 6830 | 43 |
| 7/16 | UNF | 9230 | 67 |
| 1/2 | UNF | 12500 | 104 |
| 5/8 | UNF | 19960 | 207 |
| 3/4 | UNF | 29120 | 363 |
| 7/8 | UNF | 39720 | 577 |
| 1 | UNF | 51740 | 859 |
| 1/4 | UNC | 2470 | 10 |
| 5/16 | UNC | 4100 | 21 |
| 3/8 | UNC | 6050 | 38 |
| 7/16 | UNC | 8320 | 60 |
| 1/2 | UNC | 11050 | 92 |
| 5/8 | UNC | 17620 | 183 |
| 3/4 | UNC | 26070 | 325 |
| 7/8 | UNC | 36010 | 523 |
| 1 | UNC | 47200 | 785 |
Class 8.8 Property class 8.8 High Tensile Bolts, ISO Coarse Series Threads
| Diameter (mm) | Bolt Tension Corresponding to 65% of Proof Load (kN) | Bolt Tension Corresponding to 65% of Proof Load (lbf) | Recommended Assembly Torque (Nm) | Recommended Assembly Torque (lbft) |
|---|---|---|---|---|
| 5 | 5.4 | 1210 | 5 | 4 |
| 6 | 7.6 | 1710 | 9 | 7 |
| 8 | 13.8 | 3100 | 22 | 16 |
| 10 | 21.9 | 4920 | 44 | 32 |
| 12 | 31.8 | 7150 | 77 | 57 |
| 14 | 43.4 | 9680 | 121 | 90 |
| 16 | 59.2 | 13310 | 190 | 140 |
| 18 | 74.8 | 16690 | 269 | 198 |
| 20 | 95.6 | 21490 | 370 | 270 |
| 22 | 118 | 26390 | 520 | 380 |
| 24 | 138 | 31020 | 640 | 470 |
| 27 | 177 | 39480 | 955 | 700 |
| 30 | 219 | 49230 | 1310 | 970 |
| 33 | 270 | 60330 | 1785 | 1320 |
| 36 | 319 | 71710 | 2300 | 1690 |
| (39) | 380 | 84980 | 2970 | 2190 |
| (42) | 437 | 98240 | 3670 | 2710 |
| (48) | 573 | 128820 | 5500 | 4060 |
| (56) | 792 | 178050 | 8870 | 6540 |
| (64) | 1045 | 234930 | 13380 | 9870 |
Recommended Assembly Torques – Class 10.9 Property class 10.9 High Tensile Bolts AS 1110.1
| Diameter (mm) | Bolt Tension Corresponding to 65% of Proof Load (kN) | Bolt Tension Corresponding to 65% of Proof Load (lbf) | Recommended Assembly Torque (Nm) | Recommended Assembly Torque (lbft) |
|---|---|---|---|---|
| 5 | 7.67 | 1720 | 8 | 6 |
| 6 | 10.86 | 2440 | 13 | 10 |
| 8 | 19.76 | 4440 | 32 | 24 |
| 10 | 31.27 | 7030 | 63 | 46 |
| 12 | 45.5 | 10230 | 109 | 81 |
| 14 | 62 | 13960 | 175 | 130 |
| 16 | 84.5 | 19000 | 270 | 200 |
| 18 | 103 | 23160 | 370 | 275 |
| 20 | 131.95 | 29663 | 528 | 390 |
| 22 | 164 | 36868 | 720 | 530 |
| 24 | 190.45 | 42815 | 915 | 675 |
| 27 | 248 | 55752 | 1340 | 990 |
| 30 | 302.9 | 68094 | 1820 | 1340 |
| 33 | 371 | 83405 | 2450 | 1810 |
| 36 | 440.7 | 99073 | 3170 | 2340 |
| 39 | 527 | 118470 | 4110 | 3030 |
Reference only. Coatings, lubrication and joint condition change torque requirements — confirm against the relevant standard or your engineer's specification.