Die Grinders

The die grinder is a versatile yet often overlooked power tool, valued by professionals and hobbyists alike throughout all kinds of industries. They're trusted and highly regarded amongst tradespeople for their superior torque and ability to adapt to any situation on-the-fly, thanks to a diverse range of attachments.

Cromwell stocks multiple types of die grinder, from trusted brands such as Bosch®, ATA®, Chicago Pneumatic®, 3M™ and many more.

What are die grinders?

Mini but amazingly mighty, die grinders consist of a small body, a rotating spindle and a collet holding a cutting bit at the end.

Don't underestimate them based on their size, though. The bit rotates at incredibly high RPM (rotations per minute) to quickly and effectively remove stock from a workpiece. With a wide variety of grinding bits and attachments available, the die grinder comes in useful across a wide range of applications and industries.

Why a die grinder?

The versatile die grinder is integral when performing many applications, such as deburring, polishing, grinding, chamfering and much more.

Thanks to the diversity of available attachments, die grinders can tackle tasks that other tools cannot. Small, rounded attachments allow users to work in the most awkward places, such as holes or curves surfaces. Larger attachments allow for a wider surface area when polishing or finishing surfaces.

When are die grinders used?

The die grinder is a crucial tool for countless applications. Here are some of the most common uses:

• Grinding/Reworking Dies - Unsurprisingly given the name, this is what the die grinder was originally designed for. It can quickly and effectively grind the dies used in tooling - including forging dies, stamping dies, plastic molds and much more.

• Rust Removal - Rust removal is a tough job. Once the rust has taken hold, it can be virtually impossible to remove without a die grinder. The high RPM of this tool allows rust to be removed with ease.

• Polishing - Almost all types of metal look better when polished. The round shape of die grinder polishing attachments make polishing curved and awkward shaped metals easy with a die grinder.

• Paint Stripping - Especially useful when performing automotive work, die grinders are often used for quickly stripping the paint off metal.

• Surface Smoothing - With excellent smoothing properties, a die grinder can replace sandpaper. Different attachments allow you to smoothen virtually any workable material, from hardened steel to soft woods.

• Wood Carving - An invaluable tool for carpenters and woodworkers, die grinders allow for the precise and effective carving of wood.

These are only a small selection tasks easily tackled with a die grinder. If you're looking for the best tool for your job, feel free to ask our experts for specialised advice.

Types of die grinder

Multiple types of die grinders are available; however the first main consideration is whether you want an angle die grinder or a straight die grinder.

• Straight Die Grinder   -   Your standard die grinder. Straight in design

• Angle Die Grinder   -   Functionally similar, the angle die grinder offers even greater flexibility thanks to an articulating head. This allows users to work at tougher and more complex angles, however they may be slightly more expensive to buy and maintain.

Your next consideration is power. You have two choices here - electric die grinders, or pneumatic die grinders.

• Electric Die Grinder   -   Requiring a plug to work, the electric die grinder balances power with portability. This is the most popular type of die grinder on the market thanks to its lightweight design, taking any strain away from the operator.

• Cordless Electric Die Grinder   -   Designed to provide even more portability over the regular electric die grinder, going cordless is a good choice if you're on the move or unable to work near a plug socket. The drawback is that large battery packs add bulk, making the die grinder heavier and slightly more cumbersome to use.

• Pneumatic Die Grinder   -   Harnessing the power of compressed air, pneumatic die grinders are the most powerful die grinders available and are commonly used by professionals performing heavy duty, large-scale tasks. Unfortunately when using a pneumatic tool, you'll have to carry an air compression kit around with you at all times.

Considerations when choosing a die grinder

RPM - RPM (revolutions per minute) is dependant on the power of your die grinder, with more powerful machines generally having a higher RPM. It's important to note that more isn't always better, as different abrasives come with different RPM ratings. It's worth researching the RPM rating on the abrasives you'll be working with before buying your die grinder.

Exhaust Direction - Most die grinders come with the option of a front-facing or rear-facing exhaust, which doesn't affect performance but does impact usability and user comfort. Most die grinders sold on Cromwell have a rear facing exhaust, as users tend to prefer this. However, if you use a die grinder vertically a rear exhaust will direct most of the air into your face - in which case a front facing exhaust would be preferred.

Gears vs. Gearless - The majority of die grinders are geared to achieve the perfect torque/speed ratios required for most jobs. Lately however, more and more gearless models are cropping up. Gearless models have their motor connected directly to the output of the tool, reducing maintenance costs incurred by gearing.

Die grinder jargon buster

What are the types of attachments for a die grinder?

Below are the main attachment types suitable for fitting on any die grinder:

• Grinding Bits
• Carbide Burrs
• Wood / Metal Cutting Wheels
• Grindstone Bits
• Polishing Wheels
• Wire Wheels
• Sanding Wheels

What are the colours on die grinder bits?

Die grinder attachments are typically coloured based on the type of abrasive they are. An aluminium oxide grit is typically pink or brown. Silicone carbide grits and ceramic grits are usually red, blue or green in colour.


Can you use a die grinder as a drill?

While it is technically possible, it isn't recommended to use a die grinder as a drill. The RPM on a die grinder is much higher - with RPMs of 10k+ - whereas drills are typically only a fraction of that. The high RPM of a die grinder is likely to shatter the drill bit, which can cause injury or damage to your tool.

Can a die grinder cut metal?

Absolutely - die grinders are typically used on metal, wood, and plastic.