Power tools do the cutting, grinding, drilling, sanding and finishing that hand tools cannot do at production speed. In metalwork the angle grinder is the most-used power tool by a wide margin, followed by drills, saws and die grinders.
Angle grinders are rated by disc diameter and amperage. A 4.5 in grinder at 7 A is a light-duty tool; the same size at 12-13 A has noticeably more power and holds speed under load, which matters for continuous grinding. Larger grinders (7 in and 9 in) remove material much faster but are heavier and need two hands.
Drills are rated by chuck size, amperage and speed range. A 1/2 in drill with a low-speed gear range is what cuts holes in steel; a single-speed drill will burn bits. Magnetic drills attach to steel with an electromagnet and cut holes with annular cutters — they are the practical way to drill structural steel on site.
Saws for metal include portable band saws, dry-cut saws, chop saws and reciprocating saws. Each trades speed against portability and cut quality. Dry-cut saws with carbide blades cut fast and leave a clean, cool end that needs no deburring.
Safety equipment is part of the tool: guards, handles and speed ratings are not optional. A grinder used without its guard, or with a disc rated below the tool speed, is the most common serious shop injury.
