TorqueSpec
Bolt torque database
HomeImperial9/16" Grade 2

9/16" Grade 2 Torque Spec

Low/medium carbon steel · Tensile 74,000 psi · Yield 57,000 psi

70.4
ft·lbs (dry)
95.4
N·m (dry)
52.8
ft·lbs (oiled)

Torque Values by Surface Condition

UNC — Coarse Thread — 12 TPI

Stress area: 0.182 in² · Proof load: 10,010 lbs · Clamp load (75%): 7,508 lbs

Surface Condition K Factor ft·lbs N·m in·lbs kgf·cm
Plain/Dry 0.2 70.4 95.4 844.8 972.8
Oiled 0.15 52.8 71.6 633.6 730.1
Zinc Plated 0.18 63.3 85.8 759.6 874.9
Waxed 0.1 35.2 47.7 422.4 486.4
MoS₂ 0.12 42.2 57.2 506.4 583.3
Galvanized 0.25 88.0 119.3 1056.0 1216.5

UNF — Fine Thread — 18 TPI

Stress area: 0.203 in² · Proof load: 11,165 lbs · Clamp load (75%): 8,374 lbs

Surface Condition K Factor ft·lbs N·m in·lbs kgf·cm
Plain/Dry 0.2 78.5 106.4 942.0 1085.0
Oiled 0.15 58.9 79.9 706.8 814.8
Zinc Plated 0.18 70.7 95.9 848.4 977.9
Waxed 0.1 39.3 53.3 471.6 543.5
MoS₂ 0.12 47.1 63.9 565.2 651.6
Galvanized 0.25 98.1 133.0 1177.2 1356.2

How This Value Is Calculated

Formula: T = K × D × F

Step 1 — Clamp load: F = 0.75 × 55,000 psi × 0.182 in² = 7,508 lbs

Step 2 — Torque (dry): T = 0.20 × 0.5625 in × 7,508 lbs ÷ 12 = 70.4 ft·lbs

Proof stress per SAE J429 Table 3. Stress area per ASME B1.1. K-factor per VDI 2230.

When to Use Grade 2

General-purpose, non-critical bolting. Most common ungraded hardware-store bolts.

Important Notes

  • • Torque values are for standard hex bolts with unified threads per ASME B1.1. Socket head cap screws may have different requirements.
  • • Lubrication reduces required torque significantly — using dry torque values on lubricated bolts risks exceeding yield strength.
  • • For critical or safety-related applications, always consult the manufacturer's specifications or applicable design standard.
  • • Re-used bolts may have altered friction characteristics. Inspect threads before reuse.