Angle Grinder Buying Guide

1. Introduction

An angle grinder is a handheld power tool used for cutting, grinding, sanding and polishing a variety of materials. It consists of a spinning disc mounted at a right angle to the motor shaft. These tools serve professionals and DIYers in metalworking, masonry, fabrication and finishing tasks. Choosing the right grinder involves matching power, size, discs and safety features to your projects.

An angle grinder’s core components include the electric or pneumatic motor, gearbox, spindle, disc guard and handles. The motor spins the spindle at high RPM, transferring torque through the gearbox to the disc. As the disc rotates, abrasive particles or cutting edges remove material from the workpiece. Proper ventilation, cooling and balance keep performance steady and prevent overheating.

3. Power Sources and Motor Types

• Corded (mains): unlimited runtime, consistent power, requires outlet.

• Cordless (battery): portable, limited runtime by battery capacity, heavier.

• Pneumatic (air): lightest, safe in wet environments, needs compressor and hose.

Motors may be brushed or brushless. Brushed motors cost less but require more maintenance. Brushless designs run cooler, deliver more torque per watt and last longer.

4. Disc Sizes and Arbor Standards

Common disc diameters determine cutting depth, torque demand and tool size. Arbor sizes (spindle mounts) must match disc bore:

• No-load speed (RPM): higher RPM cuts faster but may wear discs quicker.

• Power rating: amps (A) or watts (W) for corded; volts (V) and amp-hours (Ah) for cordless.

• Soft start: ramps up RPM gradually to reduce torque kick.

• Electronic brake: stops disc quickly when trigger released.

• Anti-kickback: senses stall or binding and shuts off motor.

• Variable speed dial: adjusts RPM for different tasks.

• Vibration control: dampens motor and handle vibration to reduce fatigue.

• Dust ports: allow connection of vacuum for cleaner work area.

• Spindle lock: simplifies disc changes with one tool.

6. Disc Types and Applications

• Cutting discs: thin, fast-cut wheels for metal, tile, pipe.

• Grinding discs: thicker, abrasive-bond wheels for stock removal.

• Flap discs: layered abrasive flaps for blending, finishing.

• Diamond blades: epoxy-bonded with diamond grit for concrete and stone.

• Wire brushes: cup or wheel brushes for rust and paint removal.

• Polishing pads: foam or wool for buffing and finishing surfaces.

• Sanding discs: hook-and-loop sanding sheets for wood and metal.

• Mortar rakes: rake or bit style for joint removal in masonry.

7. Material and Disc Pairing

Wear safety glasses, hearing protection, gloves and dust mask. Always use the guard and two-handed grip. Check discs for cracks before mounting and inspect arbor nuts for tightness. Stand to one side of the disc’s arc to avoid debris path. Let the grinder reach full speed before contact and never force the tool into the cut.

Clean air vents and use canned air to remove dust. Inspect and replace carbon brushes on brushed motors. Lubricate spindle threads and gearbox if user-serviceable. Store in a dry case and avoid coil kinks on power or air hoses. Test the electronic brake and anti-kickback function periodically to ensure reliability.

Decide between professional-grade and DIY lines based on usage frequency. Check compatibility with existing batteries if choosing cordless. Look for a minimum 1-year warranty and accessible service centers. Evaluate total cost of ownership including discs, batteries, brushes and attachments. Renowned brands often offer better longevity, support and tool ecosystem.

• Dust shrouds connect to vacuums for concrete grinding.

• Laser cut-line guides for straight, accurate cuts.

• Anti-vibration side handles reduce hand fatigue.

• Quick-change spindle nuts for tool-free disc swaps.

• Cord wraps, battery holsters, and case organizers streamline workflow.