the.com/torque wrench
The tool that knows the difference between snug and snapped is exactly twelve foot-pounds.
means A wrench that measures and limits how much rotational force you apply to a fastener, so you can tighten a bolt to a precise specification rather than by feel.
from The 'torque' half comes from Latin 'torquere,' to twist — the same root that gives us 'torture' (literally a twisting) and 'torment.' 'Wrench' is the older, homegrown word, from Old English 'wrencan,' to twist or wrench, related to the wrenching of the body and the cunning 'wrenches' (tricks) of medieval speech. So a torque wrench is, etymologically, a twist-twister — two words for the same motion stacked atop each other. The measuring tool itself is a far more recent thing, an early-20th-century answer to the problem of bolts that needed to be tight but not too tight.
- audible click
- Clicks when target tension is reached, no overshoot
- calibration drift
- Loses accuracy if stored under tension
- origin
- Invented in 1918 to stop loosening bolts
- head shape
- NASA torques every bolt to spec by spec
- units war
- Speaks Newton-meters and foot-pounds fluently
snap-on torque wrench — industry standard tool used by mechanics worldwide, founded 1920, dominates professional automotive shops
click-type torque wrench — most common design patented in 1960s, produces audible click when preset torque is reached