Ratcheting Mechanism
Affiliate link — we may earn a commissionThe ratcheting mechanism is a toothed gear inside the wrench head that allows rotation in one direction while freefheeling in the other. A 72-tooth ratchet moves 5 degrees per click. A 90-tooth ratchet moves 4 degrees per click. More teeth means a smaller arc swing, which matters in tight spaces where you can't rotate the handle much. Cordless ratchets motorize this mechanism so you don't have to swing at all. The motor spins the drive in the selected direction at 200 to 280 RPM, and you just hold the tool.
Why It Matters
In tight engine bays and between joists, you can't always swing a wrench more than a few degrees. A fine-tooth ratchet (72+) works in spots where a coarse one (36-tooth) can't. Cordless ratchets eliminate the problem entirely.