Type 1 vs Type 27 Grinding Wheels (How Do They Differ?)

Grinding wheels are used for smoothing and cutting through surfaces. They have versatile use in the industry. As a beginner, type 1 and type 27 grinding wheels may have you confused. 

Now, type 1 vs type 27 grinding wheels, how are they different?

Type 1 will provide the most cuts and is typically the most affordable to purchase. It’s 2-4” in diameter. Any variation from the recommended 90-degree angle will cause a fracture which happens frequently. The term “depressed center wheel” is frequently used to describe a Type 27 Cut Off Wheel.

Those are the differences in a nutshell. Choosing the right type of grinding wheels is important for the best outcome in grinding work.

I will be discussing the two types of grinding wheels in this article. Keep reading and decide which grinding wheel you need.

Differentiating Factors for Type 1 and Type 27 Grinding Wheels

A grinding wheel does the same work for metals as a cordless or corded router does for wood. Type 1 bonded grinding wheels, also known as snagging wheels, have a flat profile. These wheels are used with die grinders and range in size from 2 to 4 inches.

With its recessed center, the Type 27 design offers a variety of operating positions. Although this kind of grinding wheel can be utilized at a variety of angles. The 25 to 35-degree window provides the best performance.

 Here are the differences between the type 1 and type 27 grinding wheels in a table –

FactorsType 1Type 27
MaterialCeramic alumina, Zirconia alumina, White aluminum oxide, and Silicon carbideCeramic alumina, Zirconia alumina, White aluminum oxide, and Silicon carbide
Diameter2 - 4 inches4 - 7 inches
PurposeCuttingBlending in, Grinding corners and Flat Surfaces
ProfileStraight Profile & small diameterFlat Profile & depressed Center
PriceVariable on the materialVariable on the material

Let’s get down to the next section for a detailed discussion.

Differences In detail

Now that you glanced through the table, you know the differences between the two grinding wheels. This section discusses those differences in detail and how they serve their purposes. 

Read through carefully to find out which one you need for your grinding work.


Each grinding wheel’s materials can be divided into a few key parts. The wheels are strengthened by the grains, the bond, and the fiberglass.

These provide them the strength and stability needed for usage in demanding applications. The grit of the wheel is another crucial component that influences performance.

Materials like zirconia alumina, Ceramic alumina, silicon carbide, white aluminum oxide, and aluminum oxide. These are a few of the abrasives. That is frequently used in grinding wheels.

Type 1 wheels are used for cutting purposes, they use Zirconia Alumina blended with ceramic alumina. Other materials are also used as abrasives for type 1 wheels. 

For type 27 grinding wheels, silicon carbide with aluminum oxide works for grinding soft alloys. 

Diameter & Profile

The diameter is an important characteristic of type 1 and types 27 grinding wheels. Type 1 has a small diameter ranging from 2 to 4 inches.

It also has a straight profile which aids in cutting through tough metals sharply and easily. Type 27 wheels on the other hand have 4-7 inches in diameter.

These wheels are used for grinding. Hence they have a wider surface and a depressed center. It helps in grinding materials while collecting the excess materials that’s been ground off.


Grinding and cutting, abrasive grit is applied to Type 1 grinding wheels and cut-off wheels. Grinding wheels of type 27 are used to remove layers from metal, glass, wood, brick, or concrete.

The surfaces are sliced or notched by Type 1 cut-off wheels. Power tools and commercial equipment like bench grinders and angle grinders both require wheels.

Cup grinding wheels are used for different tasks. Like removing burrs from welds and priming surfaces for painting. Tools are made and sharpened using grinding wheels made of diamond and CBN with Type 1.

With a type 1 wheel, you can cut stainless steel rods and such with ease.

The most used abrasive grinding wheel is by far Type 27. Grinding wheels of type 27 feature a flat shape with a sunken center. Which sets them apart from other wheels.

When the operator requires work at a restricted angle, the center is depressed to provide clearance. There is a wide variety of grinding angles possible.

When using a wheel with a depressed center, often between 0 and 45 degrees. The ideal angles, however, for using type 27 grinding wheels are between 25 and 30 degrees. The cut will be more severe the steeper the grinding angle.

With these wheels, working at shallow angles necessitates considerable thought of possible consequences. Although grinding at shallow angles can extend the life of the wheel. The cut rate is frequently jeopardized at shallow angles.


When it comes to the price of grinding wheels, the price is varied. It depends on the material of the grinding wheels you are buying. 

They can start as low as $30 to as high as even $600. There are grinding wheels made of diamonds that shoot up the price ceiling really high. 

Hence the ambiguity around price. But you can find both types of grinding wheels well within your budget. 

Final Verdict

After reading through the detailed analysis, you have realized something by now. 

That there is no better type of grinding wheel between type 1 and type 27. It comes down to the user’s purpose. The grinding work you’re doing will dictate which type of grinding wheel to buy. 

In general, type 1 is used for cutting. Whereas type 27 is used for grinding various types of metal.  

Mount Type 1 and Type 27 Grinding Wheels

Proper mounting of the grinding wheels is crucial to grind work safety. Here is how you mount the grinding wheels – 

Type 1 grinder guard has a closed face while type 27 has an open face. Hub mounting type 27 wheels have a built-in threaded hub. You can directly mount the wheel on the wheel spindle without the help of any tools. 

Type 1 wheels, require proper orientation of the flanges. Ensure the wheel is centered and clamped safely. 

The gaps between the wheel and the guard provide maximum protection while working. There must be at least a 2mm gap between the guard and the wheel.

The edge and the lip of the guard direct fragments away from the user. 

The gap must be 3 to 8 mm between the new wheel and the inner surface. 

Finally,  wear gloves and glasses on all occasions to protect yourself during grind work.


What Do You Use A Type 27 Grinding Wheel For?

It’s a widely popular class of specialized abrasive instruments. Designed for rough grinding on a variety of materials, are the Type 27 grinding wheels.

They are frequently used in smaller workshops. As well as in the construction, shipbuilding, metal, engineering, chemical, and other industries.

When Should A Grinder Wheel Be Replaced?

When you are 1″ from the recess. It is a number one rule to throw the wheel away. When the machine’s guard forbids suitable grinding, detachable cup discs must be thrown away.

In this scenario, a suitable guard will determine the discard size by preventing further rim grinding.

What Grinding Wheel Is The Toughest?

Diamonds, the world’s hardest mineral, are used to make the world’s hardest grinding wheel. Diamond abrasives provide an unrivaled balance of toughness and cutting speed. Synthetic diamond crystals specially made for cutting applications are used in super abrasive diamond cutting wheels.


That concludes the discussion about type 1 vs type 27 grinding wheels. A grinding wheel typically lasts for 2 years at best. So prepare accordingly for replacements.

Hopefully after reading the article, now you know what purpose each of the grinding wheels serves. 

Was the article helpful in answering your questions? Let me know.

Jim Boslice

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