Get torque wrong and you snap a head bolt, warp a brake disc or — at the cheap end — strip a wheel stud at 70 mph on the M90. After 32 years of doing this for a living, my view is simple: buy one good torque wrench and keep it calibrated, not three cheap ones that lie to you. Here are the units we actually trust in the bay.
Click-type is the workshop standard — set the torque, pull until it clicks, job done. Beam type is old-school and unbeatably accurate but slow. Digital wrenches show real-time torque and angle (essential for modern head bolts that spec 30 Nm + 90° rotation rather than a flat torque figure). For wheels and brakes, click. For engine internals on a 2010+ car, digital with angle.
A quarter-inch drive is for sub-25 Nm fasteners — sensors, dash trim, small electricals. Three-eighths is the everyday garage wrench (10–80 Nm) — covering brakes, suspension links, most service work. Half-inch is the wheel-nut and big-bolt wrench (40–210 Nm). Don't buy one wrench to cover every range — accuracy falls off badly at the extremes of any tool's scale.
A torque wrench is a calibrated instrument. Cheap units routinely test 8–15% out of spec straight from the box — and that's the new-from-factory figure. After a year of being thrown in a toolbox they're worse. Norbar, Britool, Teng and Stahlwille hold ±3–4% out of the box and ship with a calibration certificate. That certificate matters: insurance jobs and warranty work need provable torque.
Wind a click wrench down to its lowest setting before storing — leaving it loaded crushes the internal spring and the calibration drifts. Never use it to crack tight nuts off (that's what a breaker bar's for). Get it calibrated every two years if used weekly, or before any insurance job. A £25 calibration service is cheap insurance against a stripped £400 wheel hub.
Trade use: every 12 months or 5,000 cycles. Home use: every 2 years, or before any safety-critical job (wheel nuts, brake hubs, head bolts).
Click for general servicing — simpler, no batteries, ages well. Digital if you regularly do engine internals where torque-and-angle figures are specified.
For impact-gun wheel fitting they're fine as a final-tighten safety net, but never as the primary torque source — they have wide tolerance and assume specific impact-gun output.
Bob's Mechanical Repairs — independent family-run garage in Birnam, Dunkeld, Perthshire. Call 01350 727 276 or email [email protected].