How To Choose The Best Belt Grinder For Knife Making

Topics Covered:

• Considerations When Selecting A Belt Grinder For Knife Making
• 2x72 Grinders
• 1x30 Grinders
• 1x42 Grinders
• 2x42 Grinders
• 2x48 Grinders
• 4x36 Grinders
• Contact An Abrasive Specialist

It doesn’t matter whether you make knives for a living or a hobby: the right belt grinder can make a huge difference in creating a sleek, beautiful blade. There are different machines to choose from, some of them better-suited to certain knife making processes than others. In this blog, we’ll compare some of the most popular sizes of belt grinders for knife making - and highlight their advantages, disadvantages, and recommended applications.

Considerations When Selecting A Belt Grinder For Knife Making

There are several factors you'll want to consider as you shop for a belt grinder for knife making. Belt grinders may all look similar, but specs vary from grinder to grinder, which can cause variations in performance. Grinders can also be designed for many different jobs. We've outlined some considerations below to help find a belt grinder that will work well for knife making.

Belt Size

Belt size isn't the only factor to consider when shopping for a belt sander, but it is one of the most important. The longer a belt is, the more abrasive material there is to reduce wear and heat buildup. Similarly, a wider belt can be great for removing more material at a time with larger objects, but it isn't as great for sanding smaller details.

When it comes to width, a two inch width is the perfect size for knife making. Two inches is small enough to provide accuracy while grinding without being too small for larger surface grinds. We cover each of the common belt sizes for knife making further below, but sizes to consider include: 2 x 72, 1 x 30, 1 x 42, 2 x 42, and 2 x 48.

Motor Size

Motor size is one of the most important factors when deciding on a grinder for knife making. To effectively grind steel, you need high belt speed with the ability to exert high pressure on the belt. You won’t be able to accomplish grinding very well if you don’t have a large enough motor. As a general rule of thumb, you need 1 horsepower of motor power for every inch of belt width at 72” in length. As the length of the belt is reduced, the demand on the motor is reduced. So, less power is required for smaller belt lengths.

As an example, a 2x72 belt sander would work best with a motor that has at least 2hp. On the other hand, a 2x48 grinder can work well with a motor that provides 1.5hp, because the length of the belt is shorter. 

Belt Speed

Steel grinding requires a higher belt speed than wood. So, wood-oriented grinders will have slower stock removal rates for steel. The belt speed (measured in surface feet per minute) will need to be somewhere in the range of 4,100 to 7,000 depending on the type of metal. You can calculate belt speed with the following formula: 

sfpm = (π x drive wheel diameter) x motor rpm

Variable Speed

Not all grinders have variable speed options and it isn’t entirely necessary for knife making, but it is helpful to have. Grinders with variable speed options allow you to perform heavy steel hogging at full speed while handle sanding at lower speeds. Having the ability to control speed will allow you to craft your knives with more precision and ease. 

2x72 Belt Grinders

For professional knife making, 2x72 size belts are considered the industry standard. This size accounts for the majority of belt grinding machines manufactured specifically for knife making in North America. The units are compatible with a wide range of belt materials and are surprisingly compact for the level of performance. 2x72 machines also have more accessories available, including:

• Wheel attachments ranging in size from 1/4” to 16”, for knife elements like fullering, hollow grinds, and more.
• Surface grinding attachments for cleaning and smooth, flat surfaces.
• Rotary platens for convex grinds and to mitigate the dreaded “J weight belt bump.”

The 72” belt length reduces wear and heat build-up, so you can use it during all stages of blade creation, from the initial knife development stages to finishing touches like sharpening and polishing. Because the machine has a larger working surface and often a variable speed motor, you can make knives more quickly with a 2x72 than you can with smaller belt grinders.

The biggest downside to 2x72 belt grinders is the cost. For professional knife makers, they are worth the investment, but if you’re a hobbyist or just getting started, it might make more sense to buy a smaller belt sander, like a 2x42, at least in the beginning.

Red Label Abrasives sells a knife maker abrasives kit for 2x72 belt grinders. You can choose from premium coarse ceramic grits for additional belt longevity, Edgecore ceramic for superior grinding results, ultra-fine grits for final sharpening and polishing, and more.

Which 2 X 72 inch grinder is OUR favorite? Check out Brodbeck Ironworks!

2 x 72 Belt Grinders For Knife Making

Brodbeck 2 x 72 Inch Grinder

We've worked with Brodbeck grinders for a while and we're fans of their 2 x 72 inch grinders. They have different packages available and you can save money by selecting an unassembled and unpainted kit. All of the grinders come with a 2hp motor and no welding is required for assembly.

Black Fox One 2 x 72 Inch Grinder

The Black Fox One 2 x 72 Inch Grinder is an excellent grinder with innovative features. It's easy to switch from horizontal to vertical grinding with a built-in lift assist. The grinder includes auxiliary ports for customization and an oversized 3/8" platen. The grinder is equipped with a 2hp motor.

OBM 2 x 72 Inch Grinder

The OBM 2 x 72 Inch Grinder is affordably priced at $789. It may not have as many features as some of the other grinders on the list, but it has everything you need to get the job done. The grinder is equipped with a 1.5 horsepower motor, a solid aluminum tooling arm, and a flat platen. The system is modular and you can easily add upgrades and accessories.

1x30 Belt Grinders

1x30 belt grinders are great finishing tools and an affordable investment for hobbyists. They work well for knife sharpening and detail work, but the 1” belt is not wide enough to effectively flatten off material on larger knives (although some grinders include a 6” disc sander that helps with this step). Being only 30” long, it has less abrasive surface area, so it won’t mitigate heat as well and the belts may have to be changed more often. Limited power and less clearance can also make it difficult to run thicker materials like surface conditioning belts.

If you purchase a 1x30, you’ll want to use a quality abrasive so that the machine delivers the best performance and output. Red Label Abrasives sells packages of 1x30 sanding belts with grits that range from coarse to ultra-fine, so you have long-lasting options for honing, sharpening, and polishing your blades.

1 x 30 Belt Grinders For Knife Making

Rikon 1 x 30 Inch Belt Grinder

The Rikon 1 x 30 Inch Belt Grinder includes a 5" disc sander in addition to the belt sander. The grinder is equipped with a 1/3hp motor, a 5 3/4" diameter belt table, and a 7 1/4 x 3 3/4" disc table. The motor will be a little underwhelming for knife making, but it will work on a budget.

Grizzly 1 x 30 Inch Belt Grinder

The Grizzly 1 x 30 Inch Belt Grinder also includes a 5" disc sander in combination with the belt sander. It's built with a 1/3hp motor, a 5 1/8 x 5 1/8" belt table, and a 4 x 7 5/16" disc table. Again, the motor isn't the best for knife making, but it will work on a budget.

WEN 1 x 30 Inch Belt Grinder

The WEN 1 x 30 Inch Belt Grinder is a combo sander with a 5" disc sander attached. It has a 1.5hp motor, which will work a bit better for knife making than the 1/3hp motors you typically find on 1 x 30 inch belt sanders. It features a heavy-duty base to prevent wobbling and two separate dust ports for better dust removal.

1x42 Belt Grinders

1x42 belt grinders are similar to 1x30 grinders in terms of performance. There is slightly more surface area for grinding and the machines tend to price in the more affordable range. Many professional knife makers will use both 2x72 and 1x42 grinders in their workshops. 

1x42 belts perform well for detail work and knife sharpening. You could use a 1x42 belt sander for bevel grinding, profiling, and most of the initial steps of knife development, but the lower motor power and smaller work surface associated with 1x42 grinders leaves the 2x72 grinders more equipped to create knives at a faster pace.

In many cases, it’s better to go with a 2x42 belt grinder over a 1x42 grinder. The wider belt provides more stability and the 2x42 grinders are similarly priced. 

1 x 42 Belt Grinders For Knife Making

Kalamazoo 1 x 42 Inch Belt Grinder

Kalamazoo's 1 x 42 Inch Belt Grinder is a durable steel sander. It's built with a 1/3hp motor that isn't going to break any records, but will get the job done. It's a good grinder for knife sharpening and hobby knife makers.

JET 1 x 42 Inch Belt Grinder

JET's 1 x 42 Inch Belt Grinder is a combination belt and disc sander with an 8" sanding disc. It features the same great construction you would expect from all JET grinders. It has a durable cast-iron frame with a heavy-duty steel base. The motor provides only 1/3 horsepower, so it's a better grinder for hobbyists than professionals.

Grizzly 1 x 42 Inch Belt Grinder

Grizzly's 1 x 42 Inch Belt Grinder includes an 8" disc sander. The grinder contains a 1/3hp motor, so it's not going to get the job done fast. It is a good grinder for small jobs and touch up work. It would also work well as an entry-level grinder with the low price of $269.

2x42 Belt Grinders

2x42 grinders are often designed for the woodworking market and come with a 6” disc sander on the side. They still work fairly well for knife making and are popular with hobbyist knife makers who are just starting out and need an entry-level grinder. 2x42 belts offer more stability than the 1x30 and 1x42 belts. The 6” disc can also be very handy for smaller jobs, especially beveling the front of knife handle scales.

The biggest downside for 2x42 grinders is that they usually have a 1/3hp motor. The slower motor tends to slow down as you grind, which can limit your grinding ability.

2 x 42 Belt Grinders For Knife Making

Bucktool 2 x 42 Inch Belt Grinder

Bucktool's 2 x 42 Inch Belt Grinder will work for knife makers as an affordable starter option, but it's not going to impress you with its 1/3hp motor. The grinder is designed for general purpose sanding and comes with both wood and metal-working tables. The sander also includes a 6" grinding wheel. You're definitely getting a good tool for the low price of $259.

Eastwood 2 x 42 Inch Belt Grinder

Eastwood's 2 x 42 Inch Belt Grinder is offered at the low price of $283.99. The motor is stronger than you'd find on most 2 x 42 inch grinders with a 1/2 horsepower motor. The belt drive provides 85° of adjustment and the sander includes a 6" disc sander. It would make a good entry-level grinder.

JET 2 x 42 Inch Belt Grinder

JET's 2 x 42 Inch Belt Grinder is a combo sander that includes an 8 inch disc sander. This sander does have an above average motor for a 2 x 42 inch grinder. The motor delivers 3/4hp. The grinder is built with a cast-iron frame and a heavy-duty steel base. It's a durable grinder that will last a long time. It does come at a higher price point ($649) than the other two 2 x 42 inch grinders on the list.

2x48 Belt Grinders

2x48 grinders can be a great alternative to 2x72 grinders. They are used by both professionals and hobbyists. The 2x48 belt grinders often have a larger motor than many of the other small grinding machines. The grinders can also be pretty affordable with a starting price point of around $330. The compact size of the machines allow them to fit nicely into a small workshop.

Like the other belt sizes, Red Label Abrasives sells knife making packs of 2x48 sanding belts with grits that range from coarse to ultra-fine.

2 x 48 Belt Grinders For Knife Making

Coote 2 x 48 Inch Belt Grinder

Coote makes very affordable high-quality 2 x 48 Inch Belt Grinders. The grinders are built with aluminum castings and steel throughout and all of the parts are precision machined. It's a grinder that will truly last for years if you take good care of it. Coote grinders don't come with motors and that will have to be purchased separately.

Alec Steele 2 x 48 Inch Belt Grinder

The Alec Steele 2 x 48 Inch Belt Grinder is both sleek and functional. It can easily sand almost any material (provided you're using good sanding belts) and comes equipped with a 1.5hp motor. The Alec Steele 2 x 48 Inch grinder is great for hobbyists, but it also works well for professionals.

Grizzly 2 x 48 Inch Belt Grinder

Grizzly's 2 x 48 Inch Belt Grinder is a great option for knife making. It comes equipped with a 1hp motor and a head that can pivot from 0–90° to meet your needs. The grinder has a durable cast-iron frame with a removable vertical platen. Grizzly's 2 x 48 Inch Grinder is a long-lasting, reliable grinder that you will be able to count on.

4x36 Belt Grinders

4x36 belt grinders are included on this list not because they’re good for knife making, but because we wanted to provide a warning about them. 4x36 belt grinders are very common, because they can be found in most hardware stores. 

These grinders are great for woodworking, but they are not well-suited for most knife making applications. The way most 4x36 grinders are built prevents the edge of the belt from being utilized. The weak motor and wide belt will also slow down when grinding easier than most other machines. You may be tempted to use a 4x36 grinder, especially if you already own one, but it is not ideal for knife making by any means. 

Buying A Belt Grinder Vs. Building A Belt Grinder

Knife makers are skilled craftsman with the capability to produce more than knives. Some makers will opt to build their own belt grinder instead of buying one. We actually have a full blog post on how to make your own DIY 2 x 72 inch belt sander.

Building your own belt grinder can save you money and give you the flexibility to create a sander with specs and features that meet your unique needs. It will cost you anywhere from $300-500 to build your own belt sander. You can build a grinder without having to do any welding, but some electrical knowledge will likely be required. If you read through a walkthrough and think you can build your own grinder, you'll also want to consider the time it will take. Building a grinder can be a time consuming task. You'll be able to start making knives faster if you purchase a grinder instead of making one.

Contact an Abrasive Specialist

Red Label Abrasives has been supplying knife makers with quality sanding belts and kits for over 35 years. Red Label Abrasives is a family-owned business that takes great pride in offering exceptional customer service and unrivaled technical support. To see the sizes and grits available, please visit our online store and, if you have questions or need recommendations, please call our experienced abrasives team today at 844-824-1956.

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