1" Grade 2 Torque Specification

Torque Values by Surface Condition

Stress area: 0.606 in² · Proof load: 19,998 lbs · Clamp load (75%): 14,998 lbs

Surface Condition	K Factor	ft·lbs	N·m	in·lbs	kgf·cm
Plain/Dry	0.2	250.0	339.0	3000.0	3456.9
Oiled	0.15	187.5	254.2	2250.0	2592.1
Zinc Plated	0.18	225.0	305.1	2700.0	3111.2
Waxed	0.1	125.0	169.5	1500.0	1728.4
MoS₂	0.12	150.0	203.4	1800.0	2074.1
Galvanized	0.25	312.5	423.7	3750.0	4320.6

Stress area: 0.663 in² · Proof load: 21,879 lbs · Clamp load (75%): 16,409 lbs

Surface Condition	K Factor	ft·lbs	N·m	in·lbs	kgf·cm
Plain/Dry	0.2	273.5	370.8	3282.0	3781.1
Oiled	0.15	205.1	278.1	2461.2	2835.8
Zinc Plated	0.18	246.1	333.7	2953.2	3402.8
Waxed	0.1	136.7	185.3	1640.4	1889.5
MoS₂	0.12	164.1	222.5	1969.2	2268.9
Galvanized	0.25	341.9	463.6	4102.8	4727.4

Formula: T = K × D × F

Step 1 — Clamp load: F = 0.75 × 33,000 psi × 0.606 in² = 14,998 lbs

Step 2 — Torque (dry): T = 0.20 × 1.0 in × 14,998 lbs ÷ 12 = 250.0 ft·lbs

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

Large general-purpose bolts, same grade but reduced strength at larger diameters

• 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"

Grade2

Diameter1.0" (25.40 mm)

TPI (UNC)8

Tensile60,000 psi

Yield36,000 psi

Proof33,000 psi