How to Pick the Right Bench Grinder
As a business owner, you know the importance of having the right tools for your machine shop. One essential tool is a bench grinder that allows you to sharpen, buff, and clean metal objects with speed and efficiency.
However, with so many different types of grinders on the market, it can be difficult to find the perfect one for your needs. In this article, the machine tool experts at Penn Tool Co. consider everything you must know to find the best grinder for your shop.
We’ll describe the kind of grinders that are available and the features that you should consider. Discover how you can find the best bench grinder for your operations, below.
What are the Different Types of Grinders?
There are at least 14 unique types of grinding machines available for machine shops. These include:
- Bench Grinder
- Flexible Grinding Machine
- Hand Grinder
- Pedestal Grinding Machine
- Portable Grinder
- Precision Grinding Machine
- Centreless Grinder
- Cylindrical Grinding Machine
- Form Grinder
- Internal Grinding Machine
- Plunge-Cut Grinder
- Surface Grinding Machine
- Tools-and-Cutting Grinder
- Universal Grinding Machine
Bench Grinder Wheel Types
There are at least 4 unique types of abrasive wheels available for your grinding machines. These include:
- Aluminum Oxide
- Ceramic/Aluminum Oxide
- Cubic Boron Nitride
- Silicon Carbide
Bench Grinder Review: How to Find the Best Bench Grinder for You
Finding the best heavy duty bench grinder for your machine shop can be a challenge. With so many models on the market, it’s hard to know which one is right for you and your needs.
To empower you to make an informed decision, we’ve put together this list of the top bench grinders in three categories:
Best Bench Grinder
The Precise Carbide Tool Grinder with 6″ Wheel Diameter has a range of features that make it stand out from the competition. It has a powerful 1/2 HP motor that runs at 3,450 RPM, allowing it to grind through carbide and HSS materials with ease.
The heavy-duty, cast-iron base provides maximum stability and durability, even under high-torque loads. It features two 80-grit, silicon carbide grinding wheels.
With these two wheels combined, you will have the versatility to tackle any job, no matter how tough it may be. Both wheels offer excellent performance, providing ultra-smooth cuts and finishes while reducing heat buildup during extended use periods.
Best Bench Grinder for the Money
This JET 8″ Variable Speed Industrial Buffer is one of the best bench grinders on the market. It offers a versatile and powerful grinding solution at an affordable price.
The heavy-duty buffer is designed to provide a consistent, smooth finish on all types of metals. With speeds ranging from 900 to 3,600 RPM, it can handle everything from soft metals like aluminum or brass to hard materials like stainless steel or titanium.
Best Bench Grinder Sharpening System
This Knuth Universal Workshop Multi-Grinding Machine is the best bench grinder sharpening system of 2023. It’s the perfect solution for any machine shop owner looking for a versatile and reliable sharpening system.
The unit is capable of tool and die construction, design processes, laboratory operations, mechanical production, and even training. It enables external and internal cylindrical grinding, taper grinding, and tool grinding.
Find the Right Bench Grinder for Your Shop at Penn Tool Co.
To find the best bench grinders for your operations, reach out to our team today.
Bench Grinder Wheels for Knives
A bench grinder is a useful tool that is used to carry out significant tasks of woodworking and knife repair. The bench grinder wheels for knives are spun at a high speed to trim off wood, metal, and plastic or sharpen blades. Most professional knife sharpeners use bench grinders for employing their craft.
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They are highly effective as it is cheaper to sharpen a knife instead of buying a new one.
Essentially, the cost factor is truly important in the case of chefs who invest thousands of dollars for purchasing their knives. Below we try to illustrate and provide tips for getting a perfectly sharpened edge on a blade by using a bench grinder.
Avoid Using a Vice
Most often, due to the speed of the bench grinder, people tend to use a vice. It keeps the blade in a single place as the knife is ground down to a sharp edge.
However, we recommend avoiding using the vice as the process to sharpen the blade is not a linear process. Hence, for getting a proper edge, it is important that the blade moves naturally along the grinding wheel.
A common mistake that people often make is keeping the blade flat on the bench grinder wheel. It is always advised to not sharpen the blade with the side faced against the grinder. Doing the opposite increases the shine but does not sharpen the blade. For sharpening the edges, the blade has to be a kept at an angle of 45 degrees towards the grinding wheel.
Flat knife blades mostly come with a curvature. While using a bench grinder, it is important to keep it in line with the natural curve of the blade.
While the process of sharpening the blade using the grinding wheel is carried out, it automatically starts to pull the blade towards at along this line. Hence, instead of fighting the grinding wheel, it is best advised to follow that naturally.
over, as one holds the blade over the grinding wheel, it should never be in a single place. This is because the grinding wheel moves the blade and hence it’s important to control the blade instead of fighting the natural friction of the grinding wheel.
Lastly, make sure the blade is moved along the grinding wheel in an even yet timed manner. It will eventually allow the blade to be sharpened.
Allow the Bench Grinder to Operate Freely
Most of the first time users try to put a lot of force on the blade while grinding.
However, it is not the right way forward. Doing this can make the blade chip and further destabilize the control you have over the blade. The fact that the grinding wheel spins pretty quickly, it doesn’t need the user to sharpen the blade.
The only thing that you should be doing is setting the blade on the grinding wheel in the right angle to allow it to do the work itself along the natural curvature of the blade.
Sharpening the Knife
Sharpening your knife makes it a lot easier to operate and carry the basic operations smoothly. Sharp tools are said to be dangerous when not used with the right care but applying force when using blunt tools might be a lot more dangerous. It may cause an accident in case the tools slip while applying the extra force.
Paper Sharpening Wheels for Knives
When you use paper sharpening wheels for your knives, you will find that the process is pretty fast. The time to sharpen a dull knife, for example, is often around one minute. These wheels are suitable for sharpening a variety of different blades, including knives, gouges, scissors, and carving tools.
It consists of two laminated paper wheels which can provide the blade with a polished edge. The wheels will fit on most any standard bench grinders that has a half-inch arbor that is capable of using 6-inch diameter wheels. Paper wheels like this usually work best with high-speed motors of 3450 to 3600 rpm.
Bench grinder wheels for knives are an easy tool that helps in getting the sharpness back. With constant use, the sharpness tends to fade away, and hence, it becomes more than important to sharpen the knife from time to time.
Now the Don’ts
Importance of Sharpening Your Knives
When you take care of your knives and sharpen them as they become dull, you will always have a sharp knife at your disposal for when you need it. It is just a small amount of maintenance that can ultimately save you time later.
Additionally, it is often a lot cheaper to sharpen your knives at home yourself than it is to have them professionally sharpened. As long as you learn how to sharpen your knives with your bench grinder and you follow the simple tips we have included in this article, you will be well on your way to becoming a DIY knife sharpening pro in no time.
Some Challenges of Knife Sharpening with a Grinder
You may also find that a bench grinder may be somewhat difficult to use for edge tool sharpening. The grinder is too fast and thin edges like that can become too hot and can draw the temper. For edge tool sharpening, you will instead want to consider a whetstone.
A speed controller may also be used to slow down the angle of the grinder while still being able to sharpen your knives and tools quickly and efficiently. However, you still may run the risk of overheating, so it is always advisable to proceed with caution when using your bench grinder for any kind of sharpening.
Therefore, with the right setup, the right technique and keeping the above things in mind, you can use the grinding wheels to sharpen the knives yourself.
Frequently Asked Questions?
What Happens When You Grind Aluminum On A Bench Grinder?
Aluminum is a no-no for grinding. It melts easily. Because of the heat generated by the grinder if you were to attempt to grind aluminum it would melt and coat the wheel.
When the wheel is coated with aluminum it can then cause more friction and the wheel will heat faster. IF it heats up enough it can explode.
Can You Sharpen Knives Too Much?
When you sharpen a knife you are removing a bit of the steel each time. So you are “dwindling down” your knife over time if you sharpen it too much. Think of a pencil and the change you see each time you sharpen it.
You can also damage a knife if you sharpen it incorrectly. Such as using power equipment, and overheating the steel.
It is important to hone your knife when necessary and only sharpen it a couple times a year or so depending on use. That way you are able to reduce your chances of damaging your knife.
How to Use a Bench Grinder to Sharpen Knives
Knife sharpening is a very pervasive topic. People are looking for an easy and faster way to sharpen a knife with the help of available tools, especially a bench grinder, mainly used for sharpening delicate edges. So the question is, “how do you use a bench grinder to sharpen knives?
In this article, a complete procedure is given to sharpen knives with the help of your bench grinder and some tips which might be helpful for you in this process. It would help to consider the low-voltage bench grinder for sharpening the knives. Most bench grinder operates at the speed of 3,450rpm.
When careful and keeping the wheel dressed, the high-speed grinder works better. But to sharpen, it is best to use the low voltage grinder running at 1,750rpm. The bench grinder provides a way to sharpen the knives. It has a high-speed spinning wheel for purposes like trimming wood, metal, plastic, and many other materials.
How to Use a Bench Grinder to Sharpen Knives
The bench grinder contains two wheels, which uses for different purposes. The first wheel uses for fine sharpening and accurate work. The other wheel uses for the rough sharpening. It can swap out or modify different wheels according to the user’s needs. One of the disadvantages of the bench grinder is that this tool is much more expensive.
The process is time-consuming because the material is removed little by little. The method of using the bench grinder to sharpen knives is to be done carefully. If there are no bolt holes in the bench grinder, it does not need to bol down. Do not use the wheel if you have not gone through the safety materials and have not had much training in using the tool and the wheel.
You should wear gloves when you are working with the bench grinder. The personal protective equipment includes eyewear and a face shield. The bench grinder must have enough power and the correct type of stone.
You should also use the process or any method for maintaining the proper level.avoid overheating the steel in your tool, which helps soften the cutting edge of the bench grinder. The sparks, flying chips, and much other debris are released continuously from the bench grinder at a very high speed. It can cause respiratory distress, burns, irritation, and eye injuries.
Clean the knife
First of all, you should clean the blade with the help of the wire brush and also clean the surface by using an oily rag to remove the dirt and debris from it. You should ensure that you apply the general-purpose oil because the grinder tool is prone to rust if it is not used for longer.
Monitor the blades
Then you should monitor the knife to know how many blades it contains.
The pruning knife contains two sharpening sides.
While knives contain one flat and the other side is bladed.
Sharpening the knifes
Then turn on the bench grinder and place the blade onto the tool, and it starts grinding. When pushing the edge, insert downward pressure to sharpen the knife with the straight blade. Then after taking the knife over, brush it to clean the rough edges.
The same procedure is also applied for the double-sided blade; you should keep the edge balanced.
Test for the sharpness
You should hold the sheet of paper and rest the blade at the top edge. When the knife cuts when there is minimal effort for it, it means that it is sharp.
Suppose it needs to be more vital to cut the materials efficiently, so you should repeat the same process. After sharpening the knives, wipe out the blades and store them on a dry and cool surface.
Some Tips that can be Useful while Sharpening
- It would help if you avoided the vice, as the vice keeps the blade in only one position during the grinding process. The blade must move naturally with the grinding wheel to get the right edge.
- It would help if you allowed the knife for naturally movement.
- It is necessary to maintain the correct angle. The experts suggested maintaining a 45-degree angle while sharpening the knife.
- The bench grinder runs very high speed, so it doesn’t seem easy to sharpen the knife. So the only way to reduce the bench grinder rate is to ensure it is sufficient for the sharpening tool.
- It would help if you never exerted too much force on the bench grinder.
- This mistake can cause you to lose control of the blade.
- You should set the edge on the grinding wheel at the proper angle.
The process of sharpening the knife with the bench grinder is quite a time requiring method and gives a good result without ruining the knife.
It is a complex procedure, but it can be helpful for you. To overcome this difficulty using the bench grinder, there are many ways to sharpen the knife more quickly and safely.
The paper wheel uses within many of the bench grinders. These wheels are less aggressive and quite helpful in the sharpening process. With the help of a paper wheel, you can achieve the refine edge of the knife, and it is much easier to use. You can also use the whetstone as the best way to sharpen the knives.
A bench grinder is probably not a tool you’ll use every day. However, if it’s available and set up correctly, you’ll be surprised how often it comes in handy for everything from sharpening tools to rounding over thread ends on a cutoff bolt. We’ve assembled these tips to help you get the most out of your grinder.
Keep a Container of Water Handy
Most chisels and other cutting tools are made of tempered steel. If the steel gets too hot and turns bluish black, it’s overheated and won’t hold an edge very long. To avoid ruining the edge of a tool by overheating, keep water nearby to cool the tool. A good technique is to move the tool once across the bench grinder for no more than a few seconds. Then dip it in the water. If the steel edge does overheat and turns color, grind the edge back to good steel and start over.
Grind Small Objects Safely
Hold small objects with locking pliers. This keeps your fingers a safe distance from the grinding wheel and protects them against burns from the hot metal. It also gives you better control over the grinding process.
Make Tool Sharpening Guides
Here’s a better way to hold tools securely while you’re grinding them—and take the guesswork out of creating the right bevel angle. It’s a short piece of 2×4 with an angled end and a 1-1/4-in. hole for a clamp. I made one for sharpening chisels and plane blades, and a few more with different angles for wood-turning tools. Large labels with the tool’s name tell you which blocks are for which tools. For a Delta grinder with a 6-in.-diameter wheel, a 5-1/2-in.-long piece of 2×4 aligns the tool to the wheel just right. For other bench grinders, you may need to adjust this length. Note: The angle you cut on the block is not the same as the tool’s bevel angle. But let’s skip the math. To determine the block angle, turn off the grinder and hold the tool’s bevel flush against the wheel. The angle of the tool shaft to the workbench is the angle to cut on the 2×4. Our thanks to Ray Caputo for this sharp accessory.
Consider a Low-Speed Grinder for Sharpening
Unless they’re variable speed, most bench grinders run at about 3,450 rpm. If you’re careful and keep the wheel dressed (more on that in another tip), these high-speed grinders work fine. But for sharpening garden and other tools, a low-speed grinder running at 1,750 rpm is a better choice. The lower speed reduces the chance you’ll overheat the edge of your tool. Another advantage of a low-speed grinder (100 to 150) is that this type typically includes friable white grinder wheels, which do a better job of sharpening than the gray grinder wheels usually included with high-speed grinders. See how to use an angle grinder.
Dress Wheels Frequently
Wheel dressing squares the face of the wheel, but more important, it exposes new grit for more efficient cutting. As a wheel is used, the spaces between the cutting grit can become clogged, and the grit itself dulled. A wheel in this condition can cause overheating and slows material removal. A wheel dresser like the one shown here (15 to 30) has a bar with diamond grit impregnated in it. Holding the bar against the spinning wheel cuts away the surface to expose new grit, squares the face of the wheel and rounds the wheel. To use a dressing tool like this, start the bench grinder and wait for it to reach full speed. Then press the diamond wheel dresser against the spinning wheel, holding it perpendicular to the face of the wheel. Be sure to wear a good-quality dust mask. The fine aluminum oxide dust is very bad for your lungs. Draw a pencil line on the wheel before you start to help you gauge when you’ve removed enough material from the wheel. Dress the wheel just until the pencil line disappears.
Watch for the Sparks to Come Over the Top
When you’re sharpening a chisel or other tool, you can tell when the edge is getting sharp by watching the sparks. When the edge is blunt, the sparks are deflected downward. But as the edge gets sharper, the sparks roll over the tool and cascade down the surface facing you. When you see this start to happen, be careful about grinding much more because a thin edge is very vulnerable to overheating.
Make an Angle Gauge
Chisels and other cutting tools work best if their edges are ground at the correct angle. You can search online to find the optimal angle for whatever tool you’re sharpening. Most wood chisels should be ground to about a 25-degree angle with a secondary micro-bevel angle of 30 degrees on the tip of the blade. An angle gauge allows you to set the tool rest at the desired angle. You can make an angle gauge from a thin piece of cardboard using an inexpensive protractor. 1. MARK THE ANGLE ON CARDBOARD Align the center mark on the protractor with the top edge of the cardboard. Then turn the protractor until the desired angle is also aligned with the top edge. Draw a line along the protractor to mark the angle. Don’t forget to label the angle. Cut along the line to create the gauge. 2. ADJUST THE TOOL REST Set the cardboard on the tool rest and adjust the angle of the tool rest until the wheel contacts the center of the angled portion of the cardboard gauge.
Upgrade the Tool Rest
Inexpensive bench grinders have tool rests that are finicky and difficult to adjust. If you do a lot of tool sharpening or simply want a bench grinder tool rest that’s easier to adjust, consider adding a stand-alone tool rest. There are several variations, some made for specific tasks like sharpening lathe turning tools. This Veritas model has two adjustments for positioning and aligning the tool rest, and levers for easy tightening. You can also buy an attachment that holds chisels or plane irons.
Make Your Grinder Portable
Even the most nicely organized home workshops don’t have enough bench space to devote a section to a bench grinder. A good solution is to mount your grinder to a board or small stand so you can clamp it to the bench when you need it, and store on the shelf when you don’t. The compartment on this grinder stand is a good spot to keep your dressing tool and safety glasses so they’re handy when you need them. For a fancier version, build a little drawer to fit the space under the grinder. The stand is built from two 12 x 16-in. pieces of 3/4-in. plywood separated by two 4 x 12-in. uprights. We used two 5/16-in. bolts with washers and nuts to attach the grinder, leaving enough space in front of the grinder to mount a stand-alone tool rest.
Easy-to-Clamp Mobile Base
Shazam! Fasten your bench-top tools to your workbench in seconds. Bolt 3/4-in. plywood bases on the tools and then glue and screw a wood strip along the front edge to fit into a woodworking vise. Crank this strip into a vise to lock the tool into place. If you don’t have a vise, drill a couple of clearance holes along the face of the wood strip on the base and drive screws through the strip into the edge of your workbench. Then just unscrew to remove the tool.
Set Up a Polishing Station
A bench grinder fitted with a wire wheel on one side and a cotton buffing wheel on the other side, or buffing wheels on both sides, makes a great cleaning and polishing tool. You’ll also need a set of polishing compound sticks (14). Polishing compound sticks are color coded to indicate the grit, from coarse to very fine. To use the polishing wheel, hold the stick against the buffing wheel as it spins to transfer some polishing compound to the wheel. Then hold the object lightly against the wheel and let the compound polish the surface.
Sharpen Your Lawn Mower Blade
Sharpening your lawn mower blade is easy with a bench grinder. Grind the tapered cutting edges with a grinder only if you see nicks in the blade. Follow the factory angle of the cutting edge. The grinder will remove nicks in the blade much faster than you can file them.
Not All Grinding Wheels are the Same
You can use two kinds of aluminum-oxide wheels to sharpen your chisels; one is blue-gray and the other white. We used the darker-color wheel, which is harder and will keep its shape longer. The drawback, however, is that it grinds hotter than the softer, white wheel. Too much heat will weaken the steel. The soft wheel will need more frequent shaping with a dressing tool, but you’ll be less likely to burn the edge of your chisel while grinding. For best results, use a 100-grit wheel to shape your chisel blades.
Know When to Replace a Wheel
Slide the wheel over your finger and tap the wheel in four places with a screwdriver handle. All taps should sound the same. If they don’t, scrap the wheel. It’s cracked.