Once again, with the acronyms. If there isn’t a terms and terminology book for woodworking shops, there ought to be just to keep up with the acronyms.
Key Points:
- What’s hard, doesn’t wear down, holds its round, and keeps its cool? A CBN wheel.
- CBN wheels grind cool, meaning they do not generate heat that could cause one of your tools to lose its temper.
- More expensive, yes, than other grinding choices, but for what they do and the value inherent in the task, keeping lathe tools sharp for each use gives a better turnery result on your project.
Today’s 3-letter term is CBN, and to understand the answer to the question of what grit CBN wheel to use for lathe tools, it is necessary to know what it means and why it’s important.
What Does CBN Stand For?
CBN stands for Cubic Boron Nitride. It is a synthetic material that is made by heating boron and nitrogen together under high pressure. CBN is very hard and wear-resistant, and it is often used in grinding and polishing applications. It is also used in cutting tools, such as saw blades and drill bits. CBN is a valuable material that has a wide range of applications.
For our purposes today, that application is as a sharpening agent for lathe tools.
What’s a Lathe and Its Tools?
We know what a lathe is and probably don’t have to either ask or answer the question.
A lathe is a woodworking tool that can be used to create a variety of objects from wood. It is a rotating machine that holds the wood in place while a sharp tool is used to shape it. Lathes can be used to make bowls, pens, vases, furniture legs, and other objects.
Here are some of the things you can make with a lathe in a woodworking shop:
- Bowls
- Pens
- Vases
- Candle holders
- Furniture legs
- Tool handles
- Toys
- Figurines
- Woodturnings
The piece of wood is held in place and spun; sharp tools are designed to be used with a lathe, then will remove material a little at a time as the wood spins in place until the desired shape appear. This is a great simplification of the process, and it does take a deft hand to create beautiful pieces, works of art that also double as utilitarian.
My brother is an artist, his medium is exotic woods, and instead of canvas and paint, he uses a lathe and tools that remove material from the spinning wood into his desired shape and then to sand and smooth the workpiece. Sometimes finishing oil will also be applied to the spinning wood once the surface has been prepared.
He keeps his tools sharp for each use in order to maintain the exactness of the material removal and shaping of the work piece. This is where CBN comes in.
What is A CBN Wheel?
A CBN wheel is a grinding wheel that is made of cubic boron nitride (CBN). CBN is a synthetic material that is harder than diamond, and it is often used to grind and sharpen high-speed steel, carbide, and other hard materials. CBN wheels are more durable than traditional grinding wheels, and they can produce a sharper edge.
They are also less likely to overheat the material being ground, which can help to prevent damage to the material.
CBN wheels are available in a variety of sizes, shapes, and grits. They can be used for a variety of grinding and sharpening applications, including:
- Sharpening knives
- Sharpening woodworking tools, including the tools used with lathes
- Grinding carbide inserts
- Grinding high-speed steel
- Grinding other hard materials
CBN wheels are a valuable tool for any workshop or machine shop. They are durable, sharp, and can be used to grind a variety of materials. If you are looking for a high-quality grinding wheel, a CBN wheel is a great option.
Here are some of the benefits of using a CBN wheel:
- CBN is harder than diamond which will be damaged during high-speed sharpening of hard materials, so it can grind and sharpen even the hardest materials.
- CBN wheels are more durable than traditional grinding wheels, so they last longer.
- CBN wheels produce a sharper edge than traditional grinding wheels.
- CBN wheels are less likely to overheat the material being ground, which can help to prevent damage to the material.
One could use a bench grinder, of course, to sharpen tools, including those used with lathes. A diamond wheel could be a good choice, too, but we now know that CBN is harder than diamond. Woodturning tools need to be sharp to make clean layers of material being removed, especially as you come close to the shape and curve you want your work piece to have.
With only light pressure as the tool is pushed against the spinning wheel, sharp edges from a fine sharpening will make the work easy. A better project result will come from that, and thus the need to sharpen lathe tools for each use.
While bench type grinders in the past have kept carbide steel tools sharp, as well as diamond grinders, are common and known to general woodworkers and woodworking shops and used by them to keep their saws and blades and carbide tools sharp, CBN wheels are less so, except for those engaged in turnery and hand carving (knives, chisels), where CBN wheels are better known.
A problem common in the past with grinders and tool sharpening was the heat generated when grinding steel, as the steel will lose its temper (and we don’t mean get angry here). Heat is not a problem with CBN wheels as they run cool, and so one can be more relaxed about losing the temper of a tool.
They hold their round and are carefully balanced during manufacture. The wheel is smooth aluminum, and the CBN runs around the perimeter of the wheel against which the tool is rubbed for sharpening.
How To Choose The Right CBN Wheel For Your Shop
The best CBN wheel for lathe tools is the one that best suits your needs and budget. There are a few factors to consider when choosing a CBN wheel, including:
- The grit of the wheel: The grit of the wheel determines how coarse or fine the grind will be. For general sharpening, you’ll want a wheel with a medium grit, such as 360 or 600. If you need to remove a lot of material quickly, you can use a coarser grit, such as 180. For final sharpening, you can use a finer grit, such as 1200 or 1500.
- The size of the wheel: The size of the wheel determines how much material you can grind at once. If you’re only sharpening a few tools at a time, a small wheel will be sufficient. If you’re sharpening a lot of tools, or if you’re sharpening large tools, you’ll need a larger wheel.
- The type of mount: CBN wheels are available with a variety of mounts, including bolt-on, flange, and face mount. The type of mount you need will depend on the type of grinder you have.
Once you’ve considered these factors, you can start shopping for a CBN wheel. There are a number of reputable brands that make CBN wheels, so you’re sure to find one that meets your needs.
Here are a few CBN wheels to choose from for sharpening lathe tools:
- Norton Crystolon CBN Wheels: Norton Crystolon CBN wheels are made of high-quality CBN and are available in a variety of grits and sizes. They are a good all-around choice for lathe tools.
- Alumi-Grit CBN Wheels: Alumi-Grit CBN wheels are made of aluminum oxide and CBN and are available in a variety of grits and sizes. They are a good choice for high-volume users.
- Klingspor CBN Wheels: Klingspor CBN wheels are made of high-quality CBN and are available in a variety of grits and sizes. They are a good choice for professional users.
A Little Video Demo Of A CBN Wheel in Action
In case you have never seen a CBN wheel and this is a case of first impression for you, here’s a short tutorial on grinding, sharpening, and CBN.
For the professional woodworker looking for a smooth grinding experience, CBN grinding wheels are common in the shop. Depending on the brand and the vendor, you can find an 8″ CBN grinding wheel for between $105 – $150, more than you would pay for other grinding wheels.
Are they worth the higher cost? Those who use them obviously say yes. They do cost more, but they stay true, hold their round, stay balanced, and grind cool, so you don’t have to worry about a tool losing its temper, and all of these virtues give you a great bang for the buck.