Angle grinders are often indispensable power tools that should be really be a part of any complete workshop's arsenal of equipment. Not only are angle grinders great for grinding, cutting or sanding wood, these handheld power tools can also perform similar tasks on masonry and/or stone products, and metal. Using a small wheel or disc which spins from anywhere between 8,000 to 11,000 RPM, angle grinders are best operated by letting the tool do the work. Angle grinders are typically available as corded and cordless electric power tools, but can sometimes also be pneumatic powered. These tools are categorized by the size of the wheel or disc and their amperage/wattage. Disc sizes range from 4 inches all the way up to 9 inches and larger disc sizes are more appropriate for professionals. For the average DIY'er, angle grinders between 5-9 amps should have more than enough power. Helpful features include constant torque variable speed electronics, overload protection, and greater ergonomics.