Torque Converter
Master the mechanics of N·m, lb-ft, and kg-m.
Calculate Torque from Force
Use this if you are using a "Cheater Bar" or an extension. Example: Pushing with 50lbs of force on a 2ft wrench = 100 lb-ft of torque.
The Physics of Torque
The longer the lever arm (wrench), the less force you need to apply to achieve the same torque.
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Torque Converter: The Mechanic's Essentials
Whether you are tightening the head bolts on a diesel engine, adjusting the carbon seatpost on a road bike, or simply changing a tire, precision is everything.
Our Advanced Torque Converter isn't just a calculator; it's a bridge between the Metric (N·m) and Imperial (lb-ft) worlds, ensuring you never strip a bolt or risk a mechanical failure.
Tools for the Garage
Unified Dashboard
See N·m, lb-ft, and kg-m side-by-side. No more dropdown switching.
Leverage Calculator
Input your Force (lbs) and Wrench Length (ft) to calculate the applied torque.
Mechanic Presets
One-click values for Spark Plugs, Lug Nuts, and heavy Diesel components.
Understanding Torque Specs
1. Newton Meter (N·m)
The global standard (SI Unit). Defined as the torque resulting from a force of one Newton applied perpendicularly to the end of a moment arm that is one meter long. Almost all modern vehicles (European, Asian, and American) now list engine specs in N·m.
2. Foot-Pounds (lb-ft)
The classic US standard. Defined as one pound of force applied at a one-foot radius.
Common Mistake: Do not confuse "Foot-Pounds" (Torque) with "Pound-Feet" (Energy/Work), although they are dimensionally equivalent, they are used differently in physics.
Warning: The Yield Point
Torque is actually a proxy for "Bolt Stretch" (Clamping Load). If you over-torque a bolt, it passes its elastic limit and enters the "Plastic Deformation" zone. It will permanently stretch and become weak. Once a bolt has been yielded, it must be replaced.
Frequently Asked Questions
How do I convert N·m to ft-lb?
To convert Newton Meters to Foot-Pounds, multiply by 0.73756. For example, 100 N·m is approximately 73.75 ft-lb. This is a common conversion for European car specs (N·m) being used with American tools (ft-lb).
What is the difference between lb-ft and lb-in?
There are 12 inch-pounds (lb-in) in 1 foot-pound (lb-ft). Inch-pounds are used for smaller, more delicate fasteners (like valve covers or bicycle parts), while foot-pounds are used for heavy-duty bolts (like lug nuts or suspension).
What happens if I over-torque a bolt?
Over-torquing stretches the bolt beyond its 'yield point' (elastic limit). Once stretched permanently, the bolt loses its clamping force and is prone to snapping or vibrating loose. Always use a torque wrench for critical fasteners.
How does lever length affect torque?
Torque = Force × Length. If you use a longer wrench (cheater bar), you generate more torque with the same amount of effort. For example, doubling the handle length doubles the torque applied to the bolt.
Is kg-m still used?
Kilogram-force meter (kgf·m) is an older metric unit, often found in Japanese service manuals from the 80s and 90s. Most modern manuals use Newton Meters (N·m).
Do I need to lubricate threads before torquing?
It depends. Torque specs are usually for 'clean and dry' threads unless specified otherwise. Adding oil or anti-seize reduces friction, meaning you will inadvertently apply MORE tension (clamping load) at the same torque setting, potentially breaking the bolt.