The cordless 125 mm angle grinder. Its motor and electronics sit in a sealed housing, which on a tool that lives in mineral dust is the specification that decides how long it lasts. Speed varies from about 4,500 to 8,500 rpm, so cutting and grinding each run at a sensible rate. The motor is decoupled from the housing to cut vibration, and the spindle locks with a quick-action nut so discs change without a spanner.
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