BoltGauge: Bolt Torque Chart

BoltGauge answers one shop question fast: how tight should this bolt be, and which socket do I grab?

Pick the bolt diameter, thread pitch (UNC/UNF or metric coarse/fine), grade or property class, and the finish or lubricant on the threads. The torque window updates instantly in ft·lb and N·m, with the hex socket size, recommended drive size and clamp load right beside it.

TORQUE BENCH
• Inch bolts 1/4" to 1" in SAE Grade 2, 5 and 8
• Metric bolts M6 to M24 in property class 8.8, 10.9 and 12.9
• Coarse or fine thread pitch changes the stress area and the result
• Six thread conditions with their own nut factor: dry / black oxide, clear zinc, yellow zinc, hot-dip galvanized, light oil, anti-seize
• Dial gauge shows the target window and the zone near proof load
• Adjustable preload target (60–85% of proof) in Shop settings

FASTENER PRESETS
• Save any joint — trailer tongue, motor mount, deck ledger — as a preset
• Load a preset back onto the bench with one tap
• Log every time you torque a joint and see when it was last checked

TORQUE CHART
• Full chart for any grade, pitch and finish, in both units
• Tap a row to send it to the bench
• Head-marking guide with real bolt-head images for all six grades
• Finish guide showing how coatings and lubricants change torque

SOCKETS
• Socket in hand? See which inch or metric bolts it turns, with fit rating
• Bolt-to-wrench table with ISO and DIN head sizes and socket-head hex keys
• Cross-system socket finder: the closest metric socket for an SAE head and vice versa

Works fully offline. No account, no ads, no tracking. Presets stay on your iPhone.

Torque values are estimates from the standard nut-factor equation (T = K·D·F). When an equipment or vehicle maker publishes a torque spec, use that spec.