Power Tool

Angle Grinder

Angle grinders are handheld rotary power tools that use interchangeable discs for cutting, grinding, sanding, polishing, and surface preparation.

Sizes · Discs · Controls · Materials · Safety · Articles

Angle grinder sizes and capacity

Disc diameter affects cutting depth, working area, tool size, and handling, with larger grinders trading portability for greater cutting and grinding capacity.

Size	Typical role	Strengths	Tradeoffs
4½ inch	General-purpose cutting and grinding	Compact and easy to handle	Less cutting depth
5 inch	General-purpose and medium-duty work	More capacity while remaining compact	Larger than 4½-inch models
7 inch	Heavy-duty cutting and grinding	Deeper cuts and more working area	Heavier and less maneuverable
9 inch	Large-scale cutting and grinding	High capacity and reach	Bulky and specialized

Discs and accessories

Angle grinder accessories determine the task, so diameter, mounting system, speed rating, material rating, and guard requirements must match the tool and job.

Accessory	Typical use	Key selection point
Cut-off wheel	Thin straight cuts in compatible materials	Use a wheel specifically rated for the material, tool speed, diameter, and cutting application
Grinding wheel	Stock removal, edge cleanup, and grinding	Use a grinding-rated wheel rather than using a thin cut-off wheel for side grinding
Diamond blade	Cutting compatible tile, masonry, concrete, or stone	Match the blade design and wet/dry rating to the material and grinder
Flap disc	Blending, deburring, shaping, and surface finishing	Choose an abrasive type and grit appropriate for the material and finish
Sanding disc or backing pad	Sanding and surface preparation	Use only a compatible backing system and abrasive rated for the grinder speed
Wire wheel or cup brush	Rust, scale, and coating removal	Use a grinder-rated brush of the correct mounting type and observe its maximum speed rating

Speed and controls

Angle grinders range from fixed-speed tools to models with variable speed, soft start, braking, and different switches that affect control and operation.

Feature	What it changes	Typical consideration
Fixed speed	Runs at the grinder's designed operating speed under normal conditions	Accessories must be compatible with the grinder's speed and application
Variable speed	Lets equipped models operate below their maximum speed	Useful only when the accessory and task call for a lower speed; follow the stated speed range
Paddle or dead-man switch	Requires the operator to keep the control engaged while running	The wheel can continue coasting after the switch is released unless the tool has an effective brake
Slide or lock-on switch	Can remain in the on position on models designed for latching operation	Know the switch state before connecting power or installing a battery and follow restart-protection instructions where provided
Soft start	Ramps the motor up rather than applying full startup torque immediately	Reduces the abruptness of startup on models that provide it
Electronic brake	Reduces wheel coast-down time after the switch is released	Braking time varies by model and accessory; do not treat it as an instantaneous stop

Materials and applications

Angle grinders work across many materials, but the correct accessory depends on the material and whether the job is cutting, grinding, sanding, or surface preparation.

Material or task	Typical accessory	Useful guidance
Steel and ferrous metal	Metal-rated cut-off wheel, grinding wheel, flap disc, or wire brush	Match the accessory to cutting, grinding, finishing, or cleanup rather than treating all metal work the same
Aluminum and non-ferrous metal	Accessory specifically rated for the alloy or non-ferrous use	Confirm compatibility because some abrasives can load or behave poorly on softer metals
Concrete and masonry	Compatible diamond blade, masonry wheel, grinding cup, or other rated accessory	Match the accessory to cutting versus grinding and follow dust-control requirements for the material and job
Tile and porcelain	Tile- or porcelain-rated diamond blade	Blade design affects cut quality and chipping; use an accessory specifically intended for the material
Stone	Stone-rated diamond or abrasive accessory	Different stone products vary substantially, so use the accessory manufacturer's material rating
Sanding and blending	Flap disc, sanding disc, or compatible backing pad	Choose grit and accessory type based on stock removal versus finish quality
Rust and coating removal	Wire wheel, cup brush, or suitable abrasive disc	Choose an accessory that removes the coating without unnecessarily removing the base material

Setup and safety

Safe angle grinder setup depends on the correct guard, handle, mounting hardware, accessory condition, speed rating, and secure control of the workpiece.

Setup check	Why it matters	Practical check
Guard	Helps contain fragments and separates more of the wheel from the operator	Use the guard type required for the accessory and position it according to the grinder instructions
Side handle	Improves control of a tool that can react quickly if the accessory catches or binds	Install and use the handle where the tool instructions call for two-handed control
Maximum speed rating	An accessory must be rated for the grinder's operating speed	Never use a wheel, disc, blade, brush, or backing system with a maximum RPM below the grinder's applicable speed
Mounting and flanges	Incorrect mounting can leave the accessory unsupported or improperly clamped	Use the specified flange, nut, arbor, or mounting system and confirm the accessory is seated correctly
Accessory condition	Cracks, damage, deformation, or missing components can make a rotating accessory unsafe	Inspect the accessory before use and replace damaged or questionable parts rather than testing them under load
Cutting vs. grinding	Accessories are designed for specific loading directions and operations	Do not side-load a thin cut-off wheel unless the manufacturer explicitly rates it for that use
Workpiece control	A moving workpiece can pinch the accessory or pull the grinder off line	Support and secure the workpiece appropriately for the cut, grind, or surface-preparation operation

Angle Grinder

Angle grinder sizes and capacity

Discs and accessories

Speed and controls

Materials and applications

Setup and safety

Angle grinder articles

Cutting and materials

Sizes and power

Blades and accessories

Brands and comparisons

Troubleshooting and usage

More angle grinder articles