The history
From the steelyard in a Greek market to the torque figure on a car's spec sheet: how people learned that a push is worth more further from the pivot.
People balanced loads on levers for thousands of years before Archimedes wrote down the rule. Leonardo saw that only the perpendicular distance counts, Varignon and Euler turned balance into a theory of rotation, and engineers learned to measure an engine's twist with a brake. In 1884 the twist got its own word: torque.
c. 250 BCE
Law of the lever proved
Archimedes, Syracuse
c. 1500
Perpendicular lever arm described
Leonardo da Vinci, Milan
1687
Moments of combined forces add up
Pierre Varignon, Paris
1821
Engine torque measured with a brake
Gaspard de Prony, Paris
1884
The word 'torque' in print
James Thomson, Glasgow
1938
Torque wrench sold
Paul Allen Sturtevant, United States
400 BCE – 1260
Traders weigh with steelyards, Archimedes proves the law of the lever, and medieval scholars ask how a weight's position changes its pull.
400 BCE
5th–4th century BCE
A steelyard is a balance with unequal arms: a small sliding weight far from the pivot balances a heavy load hung close to it. Greek craftsmen used it before Archimedes explained it, and Roman and Chinese steelyards appeared independently around 200 BCE.
Why it mattered. Market traders were using torque balance long before anyone wrote the rule down.
250 BCE
c. 250 BCE
In On the Equilibrium of Planes, Archimedes proved that weights balance on a lever when weight × distance from the pivot is the same on both sides. It is the principle of moments, the rule every seesaw obeys.
Why it mattered. The first exact law of torque, over 2,000 years before the word existed.
340
c. 340 CE
Pappus's Collection records the boast attributed to Archimedes: give me a place to stand and I will move the Earth. With a long enough lever arm, a small force makes any torque you like.
Why it mattered. The most famous line in physics is a statement about lever arms.
1230
early 13th century
Jordanus described 'positional gravity': a weight pulls harder or softer on a lever depending on its position and the direction it can move. He proved the law of the lever from the idea of work and solved weights on slopes.
Why it mattered. He began turning Archimedes' balance into a theory of forces at angles.
1490 – 1810
Leonardo, Stevin, Varignon, Newton, Euler and Poinsot turn the lever into a general theory of turning forces and spin.
1500
c. 1500
In his notebooks Leonardo separated a lever's real arm from its 'potential' arm: the perpendicular from the pivot to the line of the force. Pull at a slant and only that shorter distance counts. Today we call it the lever arm, r sin θ.
Why it mattered. The key to torque for forces at an angle, though his notebooks stayed unpublished for centuries.
1586
Stevin's De Beghinselen der Weeghconst set out statics in Dutch: the lever, the centre of gravity, and his wreath of spheres draped over a double slope, which shows how forces combine.
Why it mattered. It gave engineers a clear method for balancing forces and turning effects.
1687
In Projet d'une nouvelle mécanique, Varignon showed that the moment of a combined force about any point equals the sum of the moments of its parts. You can split a slanted push into pieces and add their torques.
Why it mattered. It made working out torques in real machines a matter of simple addition.
1687
In the Principia, Newton explained the slow drift of the equinoxes, first noticed by Hipparchus: the Sun and Moon pull on Earth's equatorial bulge, and that torque makes the spinning Earth's axis trace a circle every 26,000 years or so.
Why it mattered. The first explanation of precession: a torque turning a spin's direction, not its speed.
1765
In Theoria motus corporum solidorum seu rigidorum, Euler worked out how rigid bodies rotate. He named the moment of inertia and wrote the turning version of Newton's second law, which we now write τ = I α.
Why it mattered. It connected torque to spinning, not just balancing.
1803
In Éléments de statique, Poinsot showed that any set of forces on a solid body can be replaced by one force plus a 'couple': two equal, opposite forces that twist without pushing, like two hands on a steering wheel.
Why it mattered. The couple is pure torque, and it made the maths of rotation far simpler.
1817 – 1940
Brakes measure engine torque, gyroscopes show spin resisting torque, 'torque' gets its name, electric motors twist with magnetism, and wrenches click at the right torque.
1817
Bohnenberger built a heavy spinning sphere in a set of rings, which he simply called 'the Machine'. However its frame was tipped, the spinning ball kept its axis steady.
Why it mattered. The first instrument built to show how spin resists torque.
1821
Prony clamped a friction band round a drum on an engine's shaft and fixed a lever arm to it. The force on the scale at the arm's end, times the arm's length, gives the engine's torque.
Why it mattered. For the first time an engine's turning strength could be measured, not guessed.
1852
Foucault spun a heavy rotor in gimbals and watched its axis hold still while Earth turned beneath it, for the eight to ten minutes it kept spinning. He named it the gyroscope, from Greek words for 'turn' and 'watch'.
Why it mattered. Spin and torque became a tool to see Earth's own rotation.
1884
April 1884
James Thomson, an engineer and the elder brother of Lord Kelvin, used 'torque' in print in 1884, from the Latin torquere, to twist. Silvanus Thompson took it up the same year in his book on dynamos.
Why it mattered. Engineers finally had a short word for a twisting force.
1888
1885–1888
Ferraris demonstrated a rotating-field motor in 1885 and Tesla, working independently, was granted his induction motor patents in May 1888. A rotating magnetic field drags the rotor round with a steady torque, as in a ceiling fan today.
Why it mattered. Electric torque began to replace belts and steam in factories and homes.
1904
Anschütz-Kaempfe patented a gyrocompass: a fast-spinning rotor that the torque from Earth's rotation turns until it points true north. Elmer Sperry built a rival design in the United States soon after.
Why it mattered. Precession became a way to steer ships without a magnetic compass.
1918
1918 (claimed)
Conrad Bahr of the New York City Water Department said he made the first torque-limiting wrench in 1918, so water-main bolts would not be over-tightened. He and George Pfefferle patented a ratcheting torque wrench that signals the set torque in 1935.
Why it mattered. Bolts could be tightened to exactly the right torque, not by feel.
1938
Sturtevant, licensed to make a beam-type torque wrench designed at Chrysler, patented his own and became the first person to sell torque wrenches. Car makers began printing a torque for every important bolt.
Why it mattered. Tightening torque became part of every workshop manual.
1960 – today
Newton-metres on every spec sheet, tilt tests for buses, and motors that give full torque from standstill.
1960
1960 onward
The International System of Units, adopted in 1960, measures torque in newton-metres. The SI Brochure keeps the joule for energy only, even though both are a newton times a metre.
Why it mattered. One unit, two meanings: the rule stops torque being mistaken for energy.
2026
Today
Double-decker buses must lean to 28° on a tilt table without rolling over. Car specs list torque beside power, electric motors give full torque from standstill, and e-bikes measure your pedal torque to decide how much to help.
Why it mattered. From seesaws to scooters, balancing and making torque is everyday engineering.
Did you know?
Torque and energy are both a newton times a metre, but only energy is ever written in joules.
Philippe Petit crossed between the Twin Towers in 1974 with a balancing pole about 8 m long and weighing about 25 kg.
A double-decker bus, fully loaded upstairs, must lean to 28° on a tilt table without rolling over.
Your biceps pulls about eight to nine times the weight in your hand, because it attaches only about 4.5 cm from the elbow.
'Torque' comes from the Latin torquere, to twist, the same root as 'torture' and 'contortion'.
The people
c. 287 – c. 212 BCE · Mathematician and engineer · Syracuse, Sicily
Proved the law of the lever.
1452 – 1519 · Artist and engineer · Vinci, Italy
Saw that only the perpendicular 'potential lever' counts.
1548 – 1620 · Engineer and mathematician · Bruges, Flanders
Wrote the Art of Weighing on levers and centres of gravity.
1654 – 1722 · Mathematician · Caen, France
Showed that moments of forces simply add.
1707 – 1783 · Mathematician · Basel, Switzerland
Named the moment of inertia and wrote the laws of rotation.
1755 – 1839 · Engineer · Chamelet, France
Invented the brake that measures engine torque.
1819 – 1868 · Physicist · Paris, France
Named the gyroscope and used it to show Earth's rotation.
1822 – 1892 · Engineer · Belfast, Ireland
Gave torque its name in 1884.
Where it happened
Sources
Dates marked “c.” are approximate, and historians sometimes disagree about who was first. If you spot a mistake, tell us.
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