Aviation Torque Unit Converter

Convert torque between Newton meters (N·m), pound-feet (lb·ft), pound-inches (lb·in), ounce-inches (oz·in), and kilogram-force meters (kgf·m). Essential for aircraft maintenance, engine overhauls, and structural assembly where torque specs vary by manufacturer (Boeing, Airbus, Bombardier).

Torque Conversion Tool

Torque Unit Usage by Region and Manufacturer

While torque values must always be sourced from the applicable maintenance manual, unit conventions vary predictably. Aircraft maintenance manuals specify torque in different units depending on region and OEM:

Region / OEM	Primary Torque Unit	Typical Applications
Boeing (USA)	lb·in, lb·ft	Airframe structural, engine mounts
Airbus (EU)	N·m	Most airframe and system installations
Engine OEMs (CFM, P&W, GE)	N·m or lb·ft	Depends on engine program & customer spec
General Aviation (Cessna, Piper)	lb·in	Light-aircraft hardware, avionics
EASA / FAA Advisory Material	Both, with N·m preferred in newer docs	AMC/GM, ACs, SBs

Note: Always consult the current maintenance manual — torque values are critical for safety.

Torque Conversion Best Practices

Never convert in your head — use a calibrated tool (like this one) or approved conversion chart.
Round only at the final step — carry extra digits during calculation to avoid cumulative error.
Document the source unit — e.g., record “210 lb·ft (per AMM 20-51-01)” to avoid ambiguity.
Beware of “force × distance” traps — kgf·m and N·m are both metric, but not interchangeable (1 kgf·m = 9.80665 N·m).
Calibrate your torque wrench — conversion accuracy is useless if the tool isn’t traceable.

Reference: FAA AC 43.13-1B §7-2, EASA Part-145.A.30(b)

How Torque Is Specified in Maintenance Manuals

Here’s how torque instructions typically appear — and what to look for:

STEP 5: Tighten bolt (P/N XYZ) to 45 ±5 N·m.
→ Base value + tolerance, SI units

Caution: Torque to 60 in·lb (6.8 N·m). Over-torquing may damage composite fitting.
→ Dual units + safety note

Ref: Table 201, Column C — Torque: 180 lb·ft @ 70°F. Re-torque after 10 flight cycles.
→ Conditional value + maintenance note

Always verify: unit, tolerance, temperature correction, re-torque requirements, and tool calibration status.