1" Grade 5 Torque Specification

Torque Values by Surface Condition

Stress area: 0.606 in² · Proof load: 51,510 lbs · Clamp load (75%): 38,632 lbs

Surface Condition	K Factor	ft·lbs	N·m	in·lbs	kgf·cm
Plain/Dry	0.2	643.9	873.0	7726.8	8902.2
Oiled	0.15	482.9	654.7	5794.8	6676.1
Zinc Plated	0.18	579.5	785.7	6954.0	8011.9
Waxed	0.1	321.9	436.4	3862.8	4450.1
MoS₂	0.12	386.3	523.8	4635.6	5341.3
Galvanized	0.25	804.8	1091.2	9657.6	11127.2

Stress area: 0.663 in² · Proof load: 56,355 lbs · Clamp load (75%): 42,266 lbs

Surface Condition	K Factor	ft·lbs	N·m	in·lbs	kgf·cm
Plain/Dry	0.2	704.4	955.0	8452.8	9738.3
Oiled	0.15	528.3	716.3	6339.6	7304.3
Zinc Plated	0.18	634.0	859.6	7608.0	8765.5
Waxed	0.1	352.2	477.5	4226.4	4869.2
MoS₂	0.12	422.7	573.1	5072.4	5844.0
Galvanized	0.25	880.5	1193.8	10566.0	12173.4

Formula: T = K × D × F

Step 1 — Clamp load: F = 0.75 × 85,000 psi × 0.606 in² = 38,632 lbs

Step 2 — Torque (dry): T = 0.20 × 1.0 in × 38,632 lbs ÷ 12 = 643.9 ft·lbs

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

Automotive, agricultural equipment, general machinery — the most common high-strength SAE grade. Equivalent to ISO 8.8.

• 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.

Size1"

Grade5

Diameter1.0" (25.40 mm)

TPI (UNC)8

Tensile120,000 psi

Yield92,000 psi

Proof85,000 psi