7/16" Grade 5 Bolt Torque: 49.4 ft·lbs / 67.0 N·m

Torque Values by Surface Condition

UNC — Coarse Thread — 14 TPI

Stress area: 0.1063 in² · Proof load: 9,036 lbs · Clamp load (75%): 6,777 lbs

Surface Condition	K Factor	ft·lbs	N·m	in·lbs	kgf·cm
Plain/Dry	0.2	49.4	67.0	593.0	683.2
Oiled	0.15	37.1	50.3	444.7	512.4
Zinc Plated	0.18	44.5	60.3	533.7	614.8
Waxed	0.1	24.7	33.5	296.5	341.6
MoS₂	0.12	29.6	40.1	355.8	409.9
Galvanized	0.25	61.8	83.8	741.2	853.9

UNF — Fine Thread — 20 TPI

Stress area: 0.1187 in² · Proof load: 10,090 lbs · Clamp load (75%): 7,567 lbs

Surface Condition	K Factor	ft·lbs	N·m	in·lbs	kgf·cm
Plain/Dry	0.2	55.2	74.8	662.1	762.8
Oiled	0.15	41.4	56.1	496.6	572.1
Zinc Plated	0.18	49.7	67.4	595.9	686.6
Waxed	0.1	27.6	37.4	331.1	381.4
MoS₂	0.12	33.1	44.9	397.3	457.7
Galvanized	0.25	69.0	93.6	827.7	953.6

Torque by surface condition

UNC thread, ft·lbs. Values from the table above.

Same bolt, same target clamp load: thread friction alone moves the required torque from 24.7 ft·lbs (waxed) to 61.8 ft·lbs (hot-dip galvanized), 2.5× as much. Match the row to the fastener's actual finish and lubrication.

How This Value Is Calculated

Formula: T = K × D × F

Step 1 — Clamp load: F = 0.75 × 85,000 psi × 0.1063 in² = 6,777 lbs

Step 2 — Torque (dry): T = 0.20 × 0.4375 in × 6,777 lbs ÷ 12 = 49.4 ft·lbs

Proof stress per SAE J429 Table 3. Stress area per ASME B1.1. Typical K-factor, consistent with VDI 2230 friction values.

When to Use Grade 5

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

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.

Specifications

Size7/16"

Grade5

Diameter0.4375" (11.11 mm)

TPI (UNC)14

Tensile120,000 psi

Yield92,000 psi

Proof85,000 psi

7/16" Grade 5 Torque Spec