7/16" Grade 2 Bolt Torque: 32.0 ft·lbs / 43.4 N·m

Torque Values by Surface Condition

UNC — Coarse Thread — 14 TPI

Stress area: 0.1063 in² · Proof load: 5,846 lbs · Clamp load (75%): 4,385 lbs

Surface Condition	K Factor	ft·lbs	N·m	in·lbs	kgf·cm
Plain/Dry	0.2	32.0	43.4	383.7	442.0
Oiled	0.15	24.0	32.5	287.8	331.5
Zinc Plated	0.18	28.8	39.0	345.3	397.8
Waxed	0.1	16.0	21.7	191.8	221.0
MoS₂	0.12	19.2	26.0	230.2	265.2
Galvanized	0.25	40.0	54.2	479.6	552.6

UNF — Fine Thread — 20 TPI

Stress area: 0.1187 in² · Proof load: 6,528 lbs · Clamp load (75%): 4,896 lbs

Surface Condition	K Factor	ft·lbs	N·m	in·lbs	kgf·cm
Plain/Dry	0.2	35.7	48.4	428.4	493.6
Oiled	0.15	26.8	36.3	321.3	370.2
Zinc Plated	0.18	32.1	43.5	385.6	444.2
Waxed	0.1	17.9	24.3	214.2	246.8
MoS₂	0.12	21.4	29.0	257.1	296.2
Galvanized	0.25	44.6	60.5	535.5	617.0

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 16.0 ft·lbs (waxed) to 40.0 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 × 55,000 psi × 0.1063 in² = 4,385 lbs

Step 2 — Torque (dry): T = 0.20 × 0.4375 in × 4,385 lbs ÷ 12 = 32.0 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 2

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

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"

Grade2

Diameter0.4375" (11.11 mm)

TPI (UNC)14

Tensile74,000 psi

Yield57,000 psi

Proof55,000 psi

7/16" Grade 2 Torque Spec