torque converter

Unit Converters

Advanced Torque Matrix

Instantly convert torque units, visualize automotive context, and simulate wrench leverage.

N·m

lb·ft

kg·m

lb·in

Applied Torque

100.0 N·m

Automotive Context

Typical torque for car wheel lug nuts.

Leverage Simulator

Torque = Force × Distance

1.00m

Required Push Force

To generate 100 N·m

10.2 kg

~22.5 lbs / 100 N

Bolt Shear Limit (Grade 8.8)

Select bolt size to check safety

Warning: High probability of bolt shear or thread stripping!

Current torque (100 N·m) exceeds the maximum safe tightening torque (86 N·m) for M12 Grade 8.8 bolts.

How to Use the Moment of Force & Torque Converter

Step-by-step guide to converting torque units, calculating wrench leverage force, and verifying bolt shear safety limits.

Enter Torque in Any Standard Unit

Type your known torque value directly into Newton-meters (N·m), pound-feet (lb·ft), pound-inches (lb·in), or kilogram-force meters (kg·m). All other units recalculate instantaneously.

Read Precise Omni-Directional Conversions

View exact conversions across metric SI and imperial standards with zero latency, eliminating manual unit conversion math and rounding errors.

Simulate Wrench Leverage & Applied Force

Adjust the wrench length slider from 0.1 m to 3.0 m to calculate the physical push force (in kilograms, pounds, and Newtons) required to achieve the target torque.

Verify Bolt Shear Safety (Grade 8.8)

Select standard metric bolt sizes (M6 to M20) to check whether the applied torque is within safe tightening limits or risks stripping threads and snapping the bolt.

Compare Real-World Automotive Benchmarks

Relate your torque level to tangible mechanical benchmarks, from hand-tightened spark plugs and car wheel lug nuts up to V8 muscle cars, supercars, and semi-truck engines.

Copy Engineering Specifications

Click Copy Specs to copy a formatted engineering report—including converted units, leverage force requirements, bolt safety status, and automotive analogies—ready for your service logs.

Frequently Asked Questions

Physical definitions, unit conversion formulas, mechanical torque vs. energy, and fastener engineering standards.

Q:What is the difference between moment of force and torque?

In physics and mechanics, moment of force and torque describe the exact same physical principle: the rotational tendency created by a force applied at a distance from an axis (τ = r × F). In engineering practice, 'torque' typically refers to dynamic turning effort about an axle or rotating shaft (such as an engine crankshaft), while 'moment of force' (or bending moment) often refers to static rotational forces acting on beams and structures.

Q:Why is torque measured in Newton-meters (N·m) instead of Joules (J)?

Although both units share identical base dimensions (kg·m²/s²), torque is a rotational vector quantity resulting from a cross product (τ = r × F), whereas work and energy are scalar quantities resulting from a dot product (W = F · d). To avoid critical engineering confusion between rotational effort and energy expenditure, SI standards mandate that torque is expressed exclusively in Newton-meters (N·m), while energy is expressed in Joules (J).

Q:How do I convert pound-feet (lb·ft) to Newton-meters (N·m)?

Multiply pound-feet by 1.35582 to get Newton-meters (1 lb·ft = 1.355818 N·m). To convert Newton-meters to pound-feet, multiply by 0.73756 (or divide by 1.35582). For example, typical passenger car wheel lug nuts tightened to 100 N·m equal approximately 73.76 lb·ft.

Q:What is the difference between pound-feet (lb·ft) and pound-inches (lb·in)?

Because 1 foot equals 12 inches, 1 lb·ft equals exactly 12 lb·in. Pound-inches (lb·in) are used for precision low-torque fasteners—such as bicycle carbon components, motorcycle valve covers, small electronics, and engine oil pans—where using foot-pounds would be too coarse and risk over-torquing.

Q:How does wrench length affect the force required to tighten a fastener?

Torque is directly proportional to lever distance (Torque = Force × Distance). Lengthening your wrench reduces the required manual push force proportionally (Force = Torque / Length). For example, generating 100 N·m requires ~20.4 kg (200 N) on a 0.5 m wrench, but only ~10.2 kg (100 N) on a 1.0 m breaker bar.

Q:Why is correct bolt torque critical in mechanical and automotive engineering?

Tightening a bolt to its specified torque stretches the fastener within its elastic limit like a stiff spring, generating necessary clamping force (preload). Under-torquing allows cyclic vibration to loosen the joint. Over-torquing exceeds the material yield strength (bolt shear limit), permanently deforming the shank, stripping threads, or causing sudden joint failure.

τ (Tau) = F (Force) × r (Radius) × sin(θ)

τ (Tau): The Torque (Newton-meters, N·m).
F (Force): The linear force applied (Newtons, N).
r (Radius): The distance from the center (meters, m).
sin(θ): The angle between force and lever arm.

Torque converter Table

Unit	N·m	kN·m	kgf·m	kgf·cm
1 N·m	1	0.001	0.1019716213	10.1971621298
1 kN·m	1,000	1	101.9716212978	10,197.1621297793
1 kgf·m	9.80665	0.00980665	1	100
1 kgf·cm	0.0980665	0.0000980665	0.01	1

What is torque converter?

The term Torque, also known as the Moment of Force, describes the rotational equivalent of linear force. It measures how effectively a force can cause an object to rotate around a specific pivot point or axis. A Torque Converter (in a mathematical sense) is a fundamental tool used by engineers to calculate this "turning effort" or to translate values between various systems of measurement, such as Newton-meters (N·m) and Pound-feet (lb·ft).

Understanding the Values

The Lever Effect: The formula shows that torque is a product of both force and distance. This explains why a longer wrench makes it easier to loosen a rusted bolt; by increasing r, you generate more τ with the same amount of human force F.

Newton-meter (N·m): This is the standard unit of torque. One N·m is the torque resulting from a force of one Newton applied perpendicularly to a momentum arm one meter long.

Directionality: Torque is a vector. By using the "Right-Hand Rule"—curling your fingers in the direction of the rotation—your thumb points in the direction of the torque vector along the axis of rotation.

History and Origin

A History of the "Twist"

The history of the torque converter is a journey from the ancient Mediterranean to the high-performance engines of the modern world.

Archimedes and the Law of the Lever

The conceptual grandfather of torque was Archimedes (3rd century BCE). He was the first to mathematically define the law of the lever, famously claiming that with a long enough lever and a place to stand, he could move the entire Earth. He understood that distance from the fulcrum multiplied the "power" of the force, though he lacked the formal units we use today.

The Formalization of Torque

For centuries, "rotational force" was discussed vaguely. It wasn't until the late 19th century that the term "torque" was officially introduced into English scientific literature. It was suggested by James Thomson, a physicist and engineer (and the brother of Lord Kelvin), in 1884. He wanted a distinct word to separate this rotational "twist" from the linear "work" being done.

The Automotive Revolution

With the invention of the internal combustion engine, the "Torque Converter" became a household necessity for engineers. They needed to describe how much "punch" an engine could deliver to the wheels. Today, this formula is used to calibrate everything from the power output of an electric Tesla motor to the precise tension required for the bolts on a space shuttle's heat shield. It ensures that machines operate with enough "twist" to move, but not so much that they snap under the strain.