How tools actually work, and how to choose one
Find Tool Editorial Team 
A torque angle gauge measures how far a fastener rotates after it reaches an initial torque setting, rather than how hard it has been tightened. Some bolts — especially cylinder head bolts, suspension fasteners and other torque-to-yield hardware — are finished by turning them a specific number of degrees, because torque alone stops being a … Read more
A multimeter on a vehicle is used to measure voltage, resistance and current in the 12-volt electrical system — checking whether a battery is actually charged, whether a fuse has blown, whether a connector is corroded, or whether something is draining power while the car sits parked overnight. What does a multimeter actually measure on … Read more
An OBD2 scanner is a handheld or app-based device that plugs into a car’s diagnostic port and reads fault codes stored by the engine and other control units. It tells you that a system has flagged a problem and gives a code pointing at the general area — it does not tell you which part … Read more
A jack is built to lift a car, not to hold it there. Its hydraulic seal, its footprint on the ground and its single point of contact under the vehicle can all fail or shift while someone is underneath. Axle stands are designed to bear that weight safely and stay put; a jack on its … Read more
A trolley jack is a wheeled hydraulic lifting tool used to raise one corner or end of a vehicle off the ground. Axle stands are the fixed metal supports that then hold the car up. The jack does the lifting; the stands do the holding. Neither is designed to stand in for the other, and … Read more
An impact wrench is a high-torque tool built to loosen and tighten bolts and nuts using a square drive and sockets, mainly on vehicles and heavy fixings. An impact driver is a lighter, hex-drive tool aimed at driving screws and small bolts in wood, metal and general assembly work. Both use hammering internal mechanisms, but … Read more
A breaker bar is a long, solid steel handle with a socket drive on one end and no ratchet mechanism inside it. Its length gives you extra leverage, which lets you apply far more turning force than a ratchet handle can, so it’s the tool reached for when a bolt or nut is seized, rusted, … Read more
A shallow socket is short and light, made for turning a nut or bolt head that sits flush or close to the surface. A deep socket is longer, built to reach down over an extended bolt, stud, spark plug, or a nut on a threaded rod that sticks up past the fastener itself. The extra … Read more
The drive size — 1/4, 3/8 or 1/2 inch — is the size of the square peg on a ratchet or extension that a socket clips onto. It doesn’t change the size of the fastener the socket fits. It changes how much torque the tool can safely transmit, how bulky the sockets are, and how … Read more
A socket is a hollow, six or twelve-sided sleeve that fits over a bolt head or nut and is turned with a separate ratchet handle. A spanner is a fixed hand tool with a shaped jaw at one or both ends. A ratchet ring is a spanner-shaped tool with a ratcheting mechanism built into the … Read more
About what you read here. Everything on Find Tool is general information and our own editorial opinion. We research carefully and we say when the evidence is unclear, but we can be wrong, things change, and no article can know your particular situation. Please do your own research and make your own judgement rather than treating anything here as the final word. Prices, products and specifications around tools and workshop equipment change constantly, and what suits one person will not suit another. Check current details yourself, and where a decision involves real money, safety or something you cannot undo, it is worth confirming with the manufacturer, or a qualified electrician or tradesperson before you act.