Nm to ft-lbs Converter
Convert torque between Newton-meters and foot-pounds instantly. Includes inch-pounds, kilogram-force meters, and other torque units.
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Conversion Formulas
N·m to ft·lbs
Or divide by 1.356 to get the same result
ft·lbs to N·m
Multiply foot-pounds by 1.3558 for newton-meters
in·lbs to ft·lbs
Divide inch-pounds by 12 for foot-pounds
kgf·m to N·m
1 kilogram-force meter = 9.807 newton-meters
Common Torque Conversions
| N·m | ft·lbs | Typical Application |
|---|---|---|
| 1 | 0.7376 | Small fastener |
| 10 | 7.376 | Spark plug |
| 25 | 18.44 | Wheel lug nut (light) |
| 50 | 36.88 | Oil drain plug |
| 100 | 73.76 | Wheel lug nut (medium) |
| 150 | 110.6 | Wheel lug nut (heavy) |
| 200 | 147.5 | Cylinder head bolt |
| 300 | 221.3 | Axle nut |
| 400 | 295 | Crankshaft bolt |
| 500 | 368.8 | Heavy machinery |
Understanding Torque
What is Torque?
Torque is a measure of rotational force, representing how much force is applied to rotate an object around an axis. It's the product of force multiplied by the distance from the rotation point (lever arm). In mechanical applications, torque specifications ensure fasteners are tightened correctly without damage.
Newton-meters (N·m)
The newton-meter is the SI (metric) unit of torque. One newton-meter equals the torque produced by a force of one newton applied at a perpendicular distance of one meter from the axis of rotation. This unit is standard in most countries and used in scientific, engineering, and automotive applications worldwide.
Foot-pounds (ft·lbs)
The foot-pound is the imperial unit of torque commonly used in the United States. One foot-pound equals the torque produced by one pound of force applied at a distance of one foot from the rotation axis. Many American torque wrenches and automotive specifications use this unit.
Automotive Applications
- • Wheel lug nuts: Typically 80-150 N·m (60-110 ft·lbs) depending on vehicle
- • Spark plugs: Usually 15-30 N·m (11-22 ft·lbs)
- • Oil drain plugs: Generally 30-50 N·m (22-37 ft·lbs)
- • Cylinder head bolts: Often 80-250 N·m (60-185 ft·lbs)
- • Engine mounts: Typically 60-100 N·m (44-74 ft·lbs)
Why Proper Torque Matters
Under-torquing Risks
- • Fasteners may loosen over time
- • Vibration can cause parts to separate
- • Gasket leaks and seal failures
- • Loss of clamping force
- • Component failure during operation
Over-torquing Risks
- • Stripped threads
- • Broken bolts or studs
- • Warped or cracked components
- • Crushed gaskets causing leaks
- • Stress fractures in materials
Best Practices
- • Always use a calibrated torque wrench for critical fasteners
- • Follow manufacturer specifications exactly
- • Apply torque in a cross or star pattern for multiple fasteners
- • Clean threads before assembly for accurate readings
- • Consider thread lubricant requirements (wet vs dry torque specs)
Frequently Asked Questions
How do I convert Nm to ft-lbs?
Multiply the value in newton-meters by 0.7376 to get foot-pounds. For example, 100 N·m × 0.7376 = 73.76 ft·lbs. Alternatively, you can divide the N·m value by 1.356 to get the same result.
How do I convert ft-lbs to Nm?
Multiply the value in foot-pounds by 1.3558 to get newton-meters. For example, 100 ft·lbs × 1.3558 = 135.58 N·m.
What's the difference between ft-lbs and in-lbs?
Both are imperial torque units. Inch-pounds (in-lbs) are smaller - there are 12 inch-pounds in one foot-pound. In-lbs are used for smaller, more delicate fasteners where precise, lower torque is required.
Why do torque specs differ between wet and dry threads?
Lubricated (wet) threads have less friction, so the same torque produces more clamping force. Wet torque specs are typically 20-30% lower than dry specs. Always check if the specification assumes clean, dry threads or lubricated threads.
How accurate are torque wrenches?
Quality torque wrenches are typically accurate within ±4% of the indicated value when properly calibrated. Wrenches should be recalibrated annually or after being dropped. Always store a click-type torque wrench at its lowest setting to preserve calibration.
What is kgf·m and when is it used?
Kilogram-force meter (kgf·m) is a metric gravitational unit of torque used in some older specifications and certain countries. One kgf·m equals approximately 9.807 N·m. You may encounter this unit in older Japanese and European vehicle manuals.
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