#6" Grade 2 Torque Specification

Torque Values by Surface Condition

Stress area: 0.00909 in² · Proof load: 500 lbs · Clamp load (75%): 375 lbs

Surface Condition	K Factor	ft·lbs	N·m	in·lbs	kgf·cm
Plain/Dry	0.2	0.9	1.2	10.8	12.2
Oiled	0.15	0.6	0.8	7.2	8.2
Zinc Plated	0.18	0.8	1.1	9.6	11.2
Waxed	0.1	0.4	0.5	4.8	5.1
MoS₂	0.12	0.5	0.7	6.0	7.1
Galvanized	0.25	1.1	1.5	13.2	15.3

Stress area: 0.01015 in² · Proof load: 558 lbs · Clamp load (75%): 419 lbs

Surface Condition	K Factor	ft·lbs	N·m	in·lbs	kgf·cm
Plain/Dry	0.2	1.0	1.4	12.0	14.3
Oiled	0.15	0.7	0.9	8.4	9.2
Zinc Plated	0.18	0.9	1.2	10.8	12.2
Waxed	0.1	0.5	0.7	6.0	7.1
MoS₂	0.12	0.6	0.8	7.2	8.2
Galvanized	0.25	1.2	1.6	14.4	16.3

Formula: T = K × D × F

Step 1 — Clamp load: F = 0.75 × 55,000 psi × 0.00909 in² = 375 lbs

Step 2 — Torque (dry): T = 0.20 × 0.138 in × 375 lbs ÷ 12 = 0.9 ft·lbs

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

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

• 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.

Size#6"

Grade2

Diameter0.138" (3.51 mm)

TPI (UNC)32

Tensile74,000 psi

Yield57,000 psi

Proof55,000 psi