How tools actually work, and how to choose one
A straight edge is a rigid bar or blade — usually steel, sometimes granite or aluminium — with at least one edge machined to be as close to perfectly straight as the maker can manage. It is used to check whether a surface is flat, whether a line is true, and as a fence to … Read more
A feeler gauge is a set of thin, precisely made metal blades, each one a different thickness, used to measure or check a small gap between two surfaces. You slide the blade into the gap; if it fits with a slight drag, the gap matches that blade’s marked thickness. It’s a low-tech, highly reliable way … Read more
A dial indicator measures very small amounts of movement — typically a few thousandths of an inch or a few hundredths of a millimetre — and displays that movement on a dial with a sweeping needle. It is used to check that something is straight, flat, round, level, or moving exactly as far as it … Read more
A micrometer measures a dimension to a finer resolution than a caliper can reliably show, and it does so using a calibrated screw thread that applies a consistent, repeatable measuring force every time. A caliper’s sliding jaw depends on how hard the operator squeezes it — a micrometer’s ratchet stop removes that variable. That difference … Read more
A vernier caliper is a hand measuring tool with a fixed main scale and a sliding secondary scale that lets you read a length far more finely than the main scale’s markings alone. It measures outside width, inside width, depth and step height, and it needs no battery. It looks intimidating the first time you … Read more
Accuracy is how close a reading is to the true value. Precision is how consistent repeated readings are with each other, whether or not they’re correct. Resolution is the smallest change a tool can display or detect. A tool can have fine resolution and still be inaccurate, and it can be precise while being consistently … Read more
A mitre gauge is a sliding guide that fits into the slot on a table saw or band saw table. It holds the workpiece at a set angle to the blade so the operator can push the work through for a clean, repeatable crosscut or angled cut, instead of freehanding the piece against the blade. … Read more
A moisture meter tells you roughly how much water is held inside a piece of wood at the moment you test it, expressed as a percentage of the wood’s dry weight. It does not tell you whether that level is stable, whether it will change, or whether the wood is safe to build with — … Read more
A straight edge is a bar or blade made to be as perfectly straight along its length as its class of accuracy allows, used to check whether a surface or edge is flat, or to guide a marking line. A spirit level is not built or checked to that standard — its job is telling … Read more
“Measure twice” protects against the specific, repeatable ways people misread, mis-transfer, or miscalculate a number before it becomes a cut. It catches a wrong digit, a shifted reference point, or a mark on the wrong side of a line — mistakes that a single glance rarely reveals, but a second check almost always does. What … 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.