A grinder is an important tool in any do-it-yourself arsenal. When used properly, a grinder is effective at removing excess surface material from, or cutting through, various materials. And while all grinders perform similar types of action, there are different kinds of grinders available for different jobs. Understanding a grinder's uses and its limitations is essential when making a purchasing decision. In this buyer's guide, we'll take a look at the different types and styles of grinders available so you can better understand which one would be right for your project.
Electric grinders-Electric grinders are powered by electricity, and all subsequent types of grinders are available in electric versions. While they do not offer the portability of cordless grinders, electric models provide much more power. Electric grinders are also called power grinders by some manufacturers.
Cordless grinders-Cordless grinders are available only in hand-held models, as battery capacity is not strong enough to power larger types of grinders. While they are convenient and flexible, they lack the power of electric models and the precision of pneumatic models. Cordless grinders are typically best suited for those who do not need or use them that often to warrant a larger purchase.
Pneumatic grinders-A pneumatic grinder is powered by air, and these are also typically hand-held grinders. If detail or precise work is required, then a pneumatic grinder is the best fit. It is the only type of hand-held grinder that combines both precision and power for delicate grinding. Pneumatic grinders are commonly referred to as air grinders by some manufacturers.
Angle grinders-An angle grinder features a right-angled geared head that has an abrasive disc attached to it. The abrasive disc can be replaced by a variety of different discs, depending on the job. Other types of discs include grinding stones, sanding discs, diamond-blade discs, polishing pads and wire brush wheels. Angle grinders also feature an adjustable guard and a handle for two-handed operation. Angle grinders are available in all three powered versions and the following types:
- Variable speed
- Angle die
- Right angle
- Right angle die
- Mini angle
Bench grinders-A bench grinder is usually bolted to a bench or work table, and it features two abrasive discs on either side of a centrally located motor. This type of grinder is most commonly used for hand grinding, sharpening cutting tools and other forms of rough grinding. A bench grinder is also used to shape metal prior to welding and afterward to remove burrs. As with angle grinders, the abrasive discs on a bench grinder can be swapped out with other types for different jobs. Bench grinders are available only in electric-powered models and in the following types:
- Variable speed
- Mini bench
Surface grinders-Surface grinders are used primarily to provide a finish to certain materials like glass, aluminum, concrete or steel. This is a larger piece of equipment that works on flat surfaces only. There are two basic types of surface grinders-a rotary-type grinder and a planer-type. Planer-types feature a stationary grinding wheel with a movable worktable, whereas rotary-type grinders feature both a movable table and a wheel. Surface grinders are available in the following specifications:
- Rotary surface
- Concrete surface
- Manual surface
Die grinders-A die grinder is a tool used specifically for grinding the interior of cylindrical objects like pipe and tubing. A grinding nose is attached to the tip of the grinder, much in the same way a drill bit goes in a drill. This tool is used to remove the burrs and splinters left behind on the rim of pipe after it is cut. These grinders range from small, hand-held models to larger, table-mounted versions.
Belt grinders-Belt grinders are similar to belt sanders with the exception that belt grinders are used primarily for metal and other tempered materials instead of wood. This type of grinder generally performs one of three functions-finishing surfaces, deburring or stock removal. Belt grinders come in the following styles:
- Wide belt
- Stroke belt
- Platen belt
- Backstand belt
- Centerless belt
- Hand-held portable
Wet grinders-Wet grinders use water to cool and lubricate the cutting wheel as it grinds or polishes stone surfaces. This type of grinder is available in a hand-held model as well as larger tabletop and floor-stand bench models. Wet grinders are used only when working with natural stone or tile and feature abrasive wheels with a very fine grit.
Disc grinders-A disc grinder is a label that can be applied to any grinder that uses a disc. In other words, all grinders are disc grinders with the exception of belt grinders, die grinders and some surface grinders.
Drill grinders-A drill grinder is a specific piece of equipment designed to sharpen drill bits to the manufacturer's exact specifications. This type of grinder is most commonly found in metalworking shops or CNC shops that require a constant supply of accurately sharpened bits.
Grinder Wheel Accessories
Most modern disc grinders are equipped to fit a number of different types of wheels, each geared for a specific job. The most common types of accessory grinder wheels include:
- Diamond-blade cut-off discs-These discs are used for cutting through hard materials that would normally damage other discs.
- Sanding discs-These discs are used for fine sanding requirements on light metals or wood.
- Wire brush discs-Wire brush discs are used for removing rust and/or paint from metal and other hard materials.
- Polishing pads-Polishing pads are soft pads used to add shine or a finished look to a variety of materials. These are usually used along with a polishing compound.
- Grinding stones-Grinding stones are similar to but less abrasive than abrasive discs, and they're commonly used for sharpening purposes.
- Abrasive grinding discs-Abrasive grinding discs can be used for a wide number of purposes but are most commonly used for removing burrs and shaping materials.