Angle Grinder Buying Guide

Disc size

Angle grinders can accommodate a variety of different sized blades which are used for different applications. While the 125mm disc is the most common, other sizes are available including:

• 115mm / 4.5 inch disc - ideal for tasks that require manoeuvrability, with the need for accuracy and precision
• 125mm / 5 inch disc – can be used for regular grinding, cutting, sanding etc., can handle regular and heavy jobs based on power and performance of the grinder
• 150mm / 6 inch disc – similar performance to 125mm discs, while being able to handle some heavier tasks
• 230mm / 9 inch disc – for heavy duty tasks like cutting slabs. They operate slower, but can also be used for sanding or polishing

Power options

In terms of power supply, angle grinders are usually available in one of two power options:

Corded Angle Grinders

• Uses mains electricity
• Delivers constant power output
• Ideal for tasks that need continuous power

Cordless Angle Grinders

• Uses rechargeable batteries, such as our 22v Nuron Battery (or other 18/20v option)
• Offers convenience for working anywhere without needing power cables
• Ideal for jobs that require high levels of mobility

Wattage and voltage

Generally speaking, grinders with larger discs will need more power. However, the specific application will also dictate the number of watts used.

A grinder with variable speed could use differing amounts of watts depending on the speed and application. Devices will range from 500w to 2400w and more.

In terms of voltage, many brands offer corded products, as well as battery chargers for cordless products,  in either 110v or 230v models.

While this doesn’t affect the performance of the products, its main benefit is that of safety, with 110v offering less risk to users on site in the event of a shock.

Ergonomics and comfort

Angle grinders are often used for small and heavy-duty tasks. So useability from a comfort and ergonomics perspective is a big factor that shouldn’t be overlooked. This is also more important to consider if you’re going to be using a grinder for prolonged periods and frequency.

The key factors to consider for this are:

• Weight and balance: Lighter weight angle grinder models can reduce user fatigue
• Handle design: Ergonomic and anti-vibration handles improve comfort, control and safety
• Size: Compact tools can be easier to work with and offer better control

Speed (RPM)

Many grinders can operate within a certain speed range of rpm (rotations per minute) for the discs they use. Some start from 3000rpm, with models in the market available up to 12,000rpm or more.

While higher speeds are suitable for cutting and grinding harder materials, lower speeds provide more control for delicate and considered tasks like polishing. You’ll also find that many models offer adjustable speed controls, making them an all-rounder for applications across the job site.

Just remember, different tasks require different speeds and blades from your angle grinder – so a variable speed tool is a bonus across applications and materials. 

Safety features

As with any tool that’s capable of cutting and grinding, care should be taken when using an angle grinder. Most come with similar features from nearly all leading manufacturers.

• Blade guard: Almost standard on most angle grinders, protects you from sparks and debris
• Dust port option for accessories: Dust ports are available on selected grinders, such as those for concrete, which can be connected to a vacuum. Though many grinders won’t have this as an option.
• Quick disc brake: Stops the disc quickly within a few seconds after operation
• Kickback prevention: Stops the tool if the disc gets jammed on the material surface – known as Active Torque Control (ATC) on Hilti products
• Dead man’s switch: Button that requires continuous pressure to operate, turns off when button is released
• Overheating protection: Stops the tool operating if it is too hot, will only operate again once cooled down

Don’t forget, additional safety should be considered when using an angle grinder, including dust mask, earplugs, safety goggles and gloves.

Motor type: Brushless Motor vs Carbon Brushes

Many earlier tools and products, including power tools, kitchen products and washing machines, used carbon brushes as a way to transfer power from a stationary part of a motor to a moving component in order to operate. These would need constant contact between two surfaces, and over time, grind or wear down. In addition, when it comes to an efficient motor in an angle grinder, friction and heat ideally needs to minimised. As technology has developed, manufacturers have switched to using magnets and/ or a type of inverter to do the same job, without the need for contact in the motor or internal parts. These are known as brushless motors, which means that the motor could potentially last longer

However, as the build components for a brushless motor are normally more sophisticated than their carbon brush counterparts, there is a higher cost to pay for products with a brushless motor. But what you do get, is a tool that can last longer. So while a motor with carbon brushes may be cheaper, it may not last as long as you need it – or it may need to be repaired more often.