Grinders are one of the most popular tools, but we never seem to have them when we need them the most. The versatility to sharpen and cut all types of material including metal, wood, marble, concrete and much more make them a must have for DIY enthusiasts, woodworkers and masonry. The idea of finding the perfect grinder starts with what your intentions are and considering what type of grinder you need.
The two most common types of grinders are angle grinders and bench grinders. The following buyer’s guide tells you everything you need to know about angle and bench grinders including the best uses of each, how to use them, where to find them and what to look for when making your purchase.
Angle grinders are easily the most common type of grinder. These hand-held grinders are either electrical or battery operated and feature a right-angle gear head attached to an abrasive grinding disc. The disc itself is interchangeable and can be outfitted with other attachments and accessories that can be used to sharpen, cut, polish, and sand various materials such as tile, wood, concrete, marble and metals.
Types of Angle Grinders
Angles grinders are typically classified into two different types depending on the disc size:
Small angle grinders – angle grinders with discs smaller than 7-inches
Large angle grinders – angle grinders with discs 7-inches or larger
The size of angle grinders makes them highly portable and allow you to take them from jobsite to jobsite with ease. They come in many different forms including battery operated, pneumatic and electrical powered and depending on the disc size can be used on a wide array of projects.
Common Uses of Angle Grinders
The versatility and portability of angle grinders give them a wide array of uses. Some of the most common are detailed below:
Cutting – when outfitted with the proper grinding disc, can be used to cut concrete, stone, metal and other types of material. Discs with diamond tipped edges are the best for cutting as they’re much stronger and specifically made for cutting.
Grinding – the most common use and ultimately where this tool gets its name. This has become a must-have for welders and other DIY professionals which can be used to grind down welds to a smoother, flat finish.
Polishing – polishing is another common use and have become permanent fixtures in metal fabrication and automotive body shops. These tools have become great for buffing metal and can be outfitted with metal wire brushes for removal of corrosive metal, paint and rust.
Sanding – angle grinders have increased in popularity among woodworkers and automotive sanding when outfitted with a proper grit abrasive. The idea of sanding is the same; start with a coarser grit before moving to a finer grit and for optimal control, consider using a variable speed angle grinder.
Sharpening – can be used to sharpen blades, knives, lawn mower blades, but should be used in this manner with caution and should not be used to sharpen by inexperienced users.
When looking to buy an angle grinder, there are many features and terms before making your decision. We’ve detailed some of the most common below:
Adjustable guard – used to protect the user from sparks and debris that may fly off from the work piece you’re grinding. Simple adjustments can be made to the guard to protect you from any angle depending on where and how you’re using it.
Adjustable side handle – handle that provides the user more control and be moved to either side of the grinder to suit left and right-handed users.
Anti-vibration handle – provides optimal comfort to the user while reducing vibration and fatigue, especially when using for continuous, longer periods of time.
Brakes – can stop the grinding wheel in less than 2-seconds which is a great safety feature
Disc size – the larger the disc the better suited the grinder is for larger, heavy-duty tasks. The disc can range in size from 4 ½-inches to 9-inches or more with larger discs offering a larger grinding surface area and provides deeper cuts.
Safety clutch – protects the user from tool kickback which can cause injury or blemishes in the material itself
Soft start – feature seen in most large angle grinders that makes the tool easier to handle at initial startup. Users have noticed a significant decrease in turning and wrenching compared to grinder without a soft start feature.
Spindle lock – lock button control for the spindle that will keep it from turning when the nut is removed or unscrewed that holds the disc in place. Used when changing out the disc itself and is an important safety feature and makes it faster and easier to change out the disc.
Vacuum attachment – allows you to attach a vacuum to the grinder helping minimizing dust and other particles given off while using.
Variable speed – provides the user with more control and allows the user to adjust the speed which controls how fast the disc turns. Polishing and other finishing touch applications require slower speeds while cutting and other power applications require faster speeds.
Volts – 110 and 220v is conventional household electricity while 18v defines battery operated or cordless angle grinders. Cordless power gives you more flexibility and portability, but is often less powerful when compared to corded models.
Watts – larger tools will require more watts to operate
Angle Grinder Safety Considerations
Because of the velocity, speed and sheer power of the grinding discs, angle grinders can be very unsafe if used improperly. Because of this, there are numerous things to consider during use including wearing proper personal protective equipment like goggles, gloves, and hearing protection if the tool is excessively loud. Other things to consider include using in a well-ventilated area and never wear loose fitting clothing.
Bench grinders are another common type, but unlike operating it by hand like angle grinders they’re typically affixed to a bench and are less portable. These power tools are typically reserved for tougher, more abrasive projects and are permanent fixtures in machine and metal fabrication shops.
Depending on the grinding wheel attached, these grinders can be used to grind, cut, polish, sand and polish.
Bench grinders are typically classified into two types which depend on its size:
Small bench grinders – 6-inch models which run at regular speeds which is typically more then enough for most DIY tasks
Large bench grinders – 8-inch models which run at slower speeds, require less wheel changes, more versatile and widely used for fine tuning and precise grinding
The size of bench grinders makes them less portable, but are typically more powerful and better adapt for shop type work. Some models can be quite heavy and moving them from location to location just isn’t practical. Some of the most common professions include carpentry, woodworking, metal fabricators, welders, plumbers, and painters.
Bench grinders can also be classified based on the number of wheels including:
Dual wheel grinders – features two independent wheels off the same axis that rotate at the same speeds.
Mixed grinders – at least two wheels off the same axis, but may rotate either at the same speed or varying speeds. This type gives you more flexibility while accomplishing two different tasks as the same time including any combination of the following or others:
Deburring – brushing
Grinding – dry sharpening;
Shaping – wet sharpening;
Shaping with sanding belt – polishing
Common Uses of Bench Grinders
Bench grinders have become permanent fixtures in shops with some of the most common uses the same as angle grinders including cutting, grinding, polishing, sanding and sharpening. On the other hand, the finishing options may vary slightly while offering some of the following:
Deburring – removing burs or other rough edges after filing or sanding
Shaping – used to shape material including various metals
Trimming or fettling – removing larger material burrs after cutting with larger, more abrasive power tools
Bench Grinder Wheel Colors
You may have noticed the wheels of a bench grinder may vary from one to another. These colors provide more than a change of appearance, but instead offer a unique property making them better-suited for different projects. There are four colors better explained below:
Brown – best-suited for heavy-duty fettling usage
Grey – grinding steel and other harder, stronger material
Green – used for grinding of blades and made of silicone carbide
White – used for sharpening blades and other tools
When looking to buy a bench grinder, there are many features and terms before making your decision. We’ve detailed some of the most common below:
Eye shield – sits on top of the grinder and acts as a first-line defense between the tool and operator.
Coarse wheel – used for heavy-duty applications using a round stone that rotates and causes an abrasive grinding action. This allows you to cut or significantly alter the composition or shape of various material.
Fine wheel – side of the grinder wheel that’s typically used for polishing shining various metals and other material. The wheel can be replaced with a polishing brush which allows you to put finishing touches including a high-quality shine.
Spark deflector – the spark deflector is just as the name suggests and is made of a small piece of material seated between the upper and lower parts. The deflector contains the sparks when the grinder is being used and keeps them from flying everywhere.
Tool rest – hard, strong surface located just outside of the area where the wheels turn and provides a stable platform to assure even and consistent cuts. Without the tool rest, tasks would be uneven and out of alignment.
Wheel guard – when properly mounted, the wheel guard holds the wheel in place. Improperly mounting the guard is the #1 reason why the wheels must be replaced and can save a great deal of maintenance costs when installed properly.
Advantages of Using a Bench Grinder
Bench grinder have become mainstays in many shops and offer many advantages over other industrial power tools with the same purpose. Some of the most common advantages are detailed below:
Cheaper maintenance
Offers optimal control when looking at a minute level
Relatively cheap in cost
Improved versatility; can do more then just polish and grind
Simple to use
Faster results
Bench Grinder Safety Concerns
The concerns for using a bench grinder are the same as using other power tools including using ear protection, not wearing lose clothing and using in a well-ventilated area. The wheel balance is something to consider and should always be looked at prior to using. Balancing is like that of balancing car tires, if the wheel isn’t rotated or balanced properly, it can fall off.
The same idea works with making sure the wheels on a bench grinder are properly balanced always. When not balanced properly the wheels can fall off during use, especially the coarse wheel. When this happens, the rotator below the wheels can become damaged leading to expensive, and unnecessary costs.
Checking the quality of both grinding wheel is simple and only takes one step to complete. After you assure the spacing is correct, simply tap one wheel at a time and listen for a sound that resembles an audible ring. If you hear the ring, the status of the wheel is good. On the other hand, if you tap either wheel and do not hear the ring, it usually means the wheel is cracked or damaged and should not be used.
Comprehensive, Unbiased Bench and Angle Grinder Reviews
Our team of professionals have compiled the most comprehensive and 100% unbiased grinder reviews you’ll ever find. We’ve considered all aspects of both bench and angle grinders to make your buying decision much easier and odds are, if you’ve made it this far then your ready to buy. To make it simple for you, we’ve broken down the best of the best for each category of grinders which can all be seen below.
