#10" Grade 8 Torque Specification

Torque Values by Surface Condition

Stress area: 0.0175 in² · Proof load: 2,100 lbs · Clamp load (75%): 1,575 lbs

Surface Condition	K Factor	ft·lbs	N·m	in·lbs	kgf·cm
Plain/Dry	0.2	5.0	6.8	60.0	69.3
Oiled	0.15	3.7	5.0	44.4	51.0
Zinc Plated	0.18	4.5	6.1	54.0	62.2
Waxed	0.1	2.5	3.4	30.0	34.7
MoS₂	0.12	3.0	4.1	36.0	41.8
Galvanized	0.25	6.2	8.4	74.4	85.7

Stress area: 0.02 in² · Proof load: 2,400 lbs · Clamp load (75%): 1,800 lbs

Surface Condition	K Factor	ft·lbs	N·m	in·lbs	kgf·cm
Plain/Dry	0.2	5.7	7.7	68.4	78.5
Oiled	0.15	4.3	5.8	51.6	59.1
Zinc Plated	0.18	5.1	6.9	61.2	70.4
Waxed	0.1	2.9	3.9	34.8	39.8
MoS₂	0.12	3.4	4.6	40.8	46.9
Galvanized	0.25	7.1	9.6	85.2	97.9

Formula: T = K × D × F

Step 1 — Clamp load: F = 0.75 × 120,000 psi × 0.0175 in² = 1,575 lbs

Step 2 — Torque (dry): T = 0.20 × 0.19 in × 1,575 lbs ÷ 12 = 5.0 ft·lbs

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

High-strength applications, heavy equipment, critical joints, suspension components, trailer hitches. Equivalent to ISO 10.9.

• 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#10"

Grade8

Diameter0.19" (4.83 mm)

TPI (UNC)24

Tensile150,000 psi

Yield130,000 psi

Proof120,000 psi