How To Use An Angle Grinder

Learn how to use an angle grinder and understand what an angle grinder is used for with our helpful guide to mastering this popular power tool.

What is an Angle Grinder Used For?

An angle grinder is a versatile handheld power tool designed for cutting, grinding, polishing, and sanding a wide range of materials, including metal, masonry, and tile. Aside from basic cutting and grinding, an angle grinder excels at tasks such as removing rust, surface preparation, and achieving a smooth matte finish on metal surfaces with wire brush attachments.

Additionally, angle grinders are perfect for sharpening tools and blades with specialised sharpening discs, making them the perfect tool for many ~~construction,~~ renovations, and metalworking projects.

Here is a breakdown of what an angle grinder is used for:

Metalwork: Removing surplus material, smoothing welds, eliminating rust, polishing surfaces, and cutting metal bars and sheets.
Masonry: Cutting through concrete, stone, and tiles with suitable discs for precise cuts.
Tool Care: Sharpening blades for lawnmowers, garden tools, and other equipment.
Surface Prep: Stripping away old paint, rust, or dirt to prepare surfaces for painting or finishing.
Shaping & Refining: Creating clean edges, smoothing uneven surfaces, or achieving a sleek, polished look.

For best results, there are a wide selection of angle grinder sizes which match specific cutting or grinding accessories, suited to each material and application. Let’s take a deeper look at some of the uses for an angle grinder and how to approach each material in the most effective way:

Cutting

Metal: Employ a thin cut-off disc designed for metal to slice through pipes, sheets, and rebar with precision.
Stone & Tile: Attach a masonry cutting wheel to cut through concrete, brick, tiles, or natural stone, ideal for garden paths, patio repairs, or DIY renovations.
Wood: Although less frequent, specific discs made for woodworking can be used for rough cuts and shaping timber.

Grinding

Surface Grinding: Use flat, sturdy grinding wheels to remove substantial amounts of material, smooth surfaces, or create bevels suitable for welding preparations.
Edge Grinding: Smooth out rough edges and tidy up outside corner weld joints by grinding with the wheel’s edge.
Weld Grinding: Refine the appearance of welds and clear away slag residues from the welding process.

Sanding & Polishing

General Sanding: Select the appropriate discs to sand surfaces, achieving the desired smoothness or finish.
Polishing: Use specialised polishing discs to bring surfaces to a glossy, professional look after grinding.

Other Tasks

Rust & Paint Removal: Attach a wire brush to effectively clean rust, scale, and old paint from metal surfaces.
Tool Sharpening: Fit a sharpening disc to restore the edge on blades, axes, or chisels.
Deburring: Eliminate sharp or rough edges after cutting, enhancing safety and finishing quality.
Mortar Removal: Grind out old mortar from brickwork for repairs or re-pointing projects.

Can an Angle Grinder Cut Anything?

Predominantly, an angle grinder is used for either cutting or grinding metal or masonry materials.

For example, an angle grinder can be used to cut metal items such as tube, bar, plate and sheet as well as masonry items such as paving slabs, brick and concrete blocks.

It is their ability to handle different cutting/grinding discs and accessories that makes angle grinders so versatile to use. Understanding how to use an angle grinder correctly, will depend on the user matching the correct accessory to the material, for safe and effective cutting results.

Cutting Paving Slabs with an Angle Grinder

It is possible to cut paving slabs using an angle grinder, provided you select a diamond-tipped cutting disc. This technique offers a quick, accurate, and efficient way to cut through various materials such as concrete, natural stone, and porcelain, allowing for straight cuts, curves, and intricate angles. Always prioritise safety by wearing suitable personal protective equipment (PPE), including goggles, gloves, and a dust mask.

Tools & Materials Needed

Angle grinder
Diamond-tipped cutting disc
Tape measure and marking tool (chalk or pencil)
Safety gear: dust mask, goggles, gloves
Workbench and clamps to ensure the slab is secured
Spray water bottle

Step-by-Step Process

Preparation: Secure the paving slab firmly on a stable work surface or workbench using clamps to prevent movement during cutting.
Marking: Carefully measure and mark the desired cut line on the slab with a pencil or chalk for accuracy.
Safety: Pop your safety goggles on, gloves, and dust mask before beginning.
Cutting:
- Power up the angle grinder and gently guide it along your marked line.
- Maintain steady, consistent pressure and keep the speed even throughout the cut.
- For porcelain slabs, continuously apply water to keep the blade and material cool, reducing the risk of overheating or cracking.
- Cutting on a bed of sand can help minimise vibration and improve control.
- Finishing: Once the cut is complete, inspect the edges, removing any loose debris, and tidy them up as needed.

Essential Tips for safely cutting paving slabs

Secure Clamping: Make sure the slab is tightly clamped to prevent any movement while cutting, which helps ensure a clean, straight cut.
Choose the Right Blade: Always use a diamond-tipped disc appropriate for cutting masonry, stone, or concrete.
Manage Dust & Heat: Use water to keep the blade cool and suppress dust - this is especially important for porcelain and other dust-sensitive materials.
Patience is Key: Take your time during the cut; forcing the tool can lead to accidents or damage.
Seek Assistance: For heavy or large slabs, having another person to help can make the process much safer and easier.

Cutting Wood with an Angle Grinder

You can cut wood using an angle grinder, but it’s important to use a specialised wood-cutting blade rather than a standard metal-cutting disc. Using a metal grinding disc for wood is risky, as it produces excessive heat, friction, and smoke, which can cause the tool to overheat or even lead to injury. Ensure the wood is securely clamped, wear appropriate safety gear, and maintain a firm, two-handed grip to stay in control and prevent kickback. Carefully guide the blade along your marked line, applying gentle pressure and cutting from top to bottom for a safer, cleaner cut.

Required Blade & Safety Measures

Wood-Cutting Blade: Avoid using a standard metal grinding disc. Instead, select a blade specifically designed for wood - featuring large carbide teeth or a serrated edge.
Safety Gear: Always wear gloves and eye protection when operating an angle grinder.
Clamping Materials: Secure the workpiece firmly to a stable surface to prevent movement and minimise vibrations.
Two-Handed Grip: Hold the angle grinder with both hands for maximum control and stability.
Blade Guard: Position the guard so that it directs away from your body while allowing the blade to sink into the wood safely.
Blade Direction: Confirm the blade teeth point in the correct direction of rotation, often indicated by an arrow on the wheel.

Cutting Technique

Mark the Cut: Use a pencil or chalk to clearly mark your designated cut line on the wood.
Position the Blade: Rest the guard against the workpiece, then slowly sink the blade into the material from above.
Apply Light, Steady Pressure: Do not force the blade; let the tool do the work while maintaining a gentle, consistent pressure.
Cut in a Straight Line: Guide the blade carefully along the marked line, keeping movements smooth and controlled.
Maintain Control: Use both hands, keeping a firm grip to avoid kickback. Do not push too hard - let the blade do the cutting.
Thick Materials: For thicker pieces, you might need to make multiple passes or flip the workpiece and cut from the opposite side.
Safety Stance: Stand slightly offset from the blade’s path, positioning yourself at an angle to protect yourself in case the blade binds or comes loose.

Angle Grinder Vs Straight Grinder

It is helpful to differentiate between types of grinders when choosing the best tool for the job.

Here are the key features of an Angle Grinder Vs Straight Grinder:

An angle grinder typically has a long straight body/handle with a metal gearbox at the end which converts the drivetrain by 90° and drives an abrasive or diamond disc.
An angle grinder incorporates a spark guard to protect the user from sparks and debris.
A straight grinder, or more commonly, a die grinder, is typically a long straight bodied tool which has a small chuck on the end and is typically used for de-burring metallic materials, grinding back weld lines or fine sanding of metallic parts.

Cordless Angle Grinder

The most common types of angle grinder tools are powered by electricity; either corded or battery powered.

Cordless grinders can be used for the exact same applications as corded grinders, as they are typically produced in the same sizes and produce a similar RPM.

Going cordless, battery pack operated will give you the freedom to move when using your angle grinder for handiwork. A cordless angle grinder, such as the Ryobi 18V ONE+™ R18AG-140S 115mm Cordless Angle Grinder Starter Kit is perfect for sharpening blades, removing rust, cutting patio slabs and so much more.

Operated by a two stage non-lockable switch for enhanced user safety makes this the perfect tool for DIY novices as well as more experienced users.

✓ Featuring a three position handle for increased flexibility as well as better control when grinding or cutting.
✓ Two stage non-lockable switch for enhanced user protection preventing accidental start up
✓ GripZone+ overmould handle increases user comfort and control
✓ Using the inclusive 4.0Ah battery, the Ryobi R18AG-140S can deliver up to 46 cuts of 13mm threaded bar on a single charge. Considerations for Cordless Angle Grinders

What to Look For in a Cordless Angle Grinder

There are several angle grinder sizes to match different applications so you must ensure you choose based on the work you need to complete.

The main things to look for in a cordless angle grinder are disc diameter, max RPM and switch type.

Switch type can be an important feature depending on safety requirements and environment:

The two main switch types are Lock-On and Paddle/Dead Man Switch.

A Lock-On switch can be locked on as the name suggests, freeing up the user's hands to control the tool.
A Paddle switch must be constantly pressed or squeezed by the users hand or finger to ensure the angle grinder operates. If the user lets go or the angle grinder is dropped, the switch s released which stops the tool from working.

There are several types of angle grinder disc, but the three most common types are Abrasive, Diamond and Flap Disc:

Abrasive discs are the most common and cheapest on the market. They are produced to suit applications such as cutting & grinding metal.
Diamond discs are best suited to cutting masonry materials such as concrete slabs & blocks, sandstone and brick. Diamond discs are not used for grinding.
Flap Discs are typically constructed with a composite material base with sanding pads adhered to the structure. This type of disc is typically used for grinding weld lines, removing rust and smoothing metallic objects before polishing.

Is a Brushless Angle Grinder the Best Option?

Another alternative may be a brushless angle grinder, so knowing whether a brushless angle grinder is worth investing in may come down to the battery life.

Brushless angle grinders’ battery life can be affected by several factors. For the best runtime per charge, a brushless angle grinder with a high capacity battery such as 4Ah, 5Ah or 9Ah will give the best results.

If you use an angle grinder on a regular basis or need extra power then yes, brushless is the way to go. Brushless grinders typically offer much higher RPM's when compared to brushed models, so will offer more power. Brushless motors are much more efficient too, resulting in longer battery life per charge.

Choosing the Best Angle Grinder

If you need to cut or grind metal, or cut paving slabs or walling then an angle grinder is worth investing in. We have a variety of angle grinders and accessories to fit each model, suitable for your next DIY project.