Tools & Power Tools Department

A brushed motor uses carbon brushes rubbing on a commutator to switch current as the motor turns. That contact wears, wastes energy as heat and eventually needs replacing. A brushless motor does the switching electronically instead, so less energy is lost, the tool runs cooler, the motor lasts longer, and it can sense load and adjust. In practice you get more runtime per charge and a lighter tool for the same power, at a higher purchase price.

Tooth count is the short answer. Fewer, larger teeth cut fast and rough, which is what you want ripping framing lumber; more teeth cut slower and cleaner, which is what you want crosscutting trim or plywood you will see. A 24-tooth circular blade is a framing blade; a 60- or 80-tooth is a finish blade. For reciprocating saws, tooth pitch and blade material matter more than length — bi-metal for mixed material and demolition, finer teeth for metal.

They are not the same tool. A drill applies steady rotation and is what you want for drilling holes and for anything needing controlled torque, like a hole saw or a spade bit. An impact driver adds rapid rotational hammering, which drives long screws and lags with far less strain on your wrist, but it is loud and too aggressive for delicate work. Most people who do both end up owning both, which is why they are so often sold as a pair.