*Pneumatic grinder* = an air-powered grinder. Instead of electricity or battery, it runs on compressed air from an air compressor.
They're the go-to for workshops, auto body, and metal fab because they're light, fast, and don't overheat.
*Main types*
**Type** **Shape** **Best for**
**Angle Grinder** 90° head Cutting, grinding, rust removal. 4" and 5" discs
**Straight/Die Grinder** Pencil shape Detail work, porting, deburring. Uses 1/4" and 6mm bits
**Vertical Grinder** Inline handle Surface grinding, weld grinding. 5" - 7" discs
**Orbital Sander** Round pad Bodywork, paint prep, finishing
*Key specs to check*
**Spec** **What it means**
**Disc Size** 4" = most common. 5" = faster material removal. 7" = heavy grinding
**RPM** 10,000 - 22,000 RPM. Die grinders can hit 25,000 RPM
**Air Consumption CFM** How much air