Grinder Tools
Grinder tools remove material from work pieces by abrasion. A grinder tool can be used to roughly shape material, smooth a nearly finished surface, and even apply a high polish to a finished piece. There are many types of grinding tools and accessories for them.
Power tool grinders are driven by either electricity or compressed air. An electric grinder is seldom cordless, because grinders consume a great deal of energy; a battery would not last very long. An air grinder is common in industrial settings and automotive repair shops, where the tool is often used for long periods of time. Air tools are much lighter than electric tools due to their lack of motors, and therefore are less fatiguing to hold and use for long periods.
Industrial grinders are often bench-mounted, larger versions of consumer grinders. Some industrial grinders are mounted on articulated robotic arms so that they can rapidly grind large metal parts in pre-programmed shapes. A die grinder is used to shape dies, and the dies are then used to stamp sheet metal into desired shapes. A tool post grinder is a stationary grinder against which a work piece is held and moved to shape it.
A belt grinder is a circular band of abrasive-impregnated flexible backing material which rapidly travels around two pulleys. The band flexes depending on how much pressure is applied to the work piece, making a more or less curved cut in the piece. With less pressure, one gets a straight, polished surface.
Angle grinders are common in many workshop and industrial settings. A spinning abrasive wheel is set at an angle to the motor's shaft. The angle grinder makes short work of many grinding chores, and can even be used as a cut-off wheel to sever pipe and rods.
Grinders use pads, drums, belts, and other consumable items impregnated with abrasive materials. The fineness of the abrasive grit determines how fast material is removed and how smooth finish is. Coarser grits are used to roughly shape materials, and finer grits for finishing and polishing. Grinders can also be fitted with soft cloth or lambswool pads onto which liquid polishing compounds or very fine abrasives called rouge can be applied.
Tool grinders are used to sharpen the edges of cutting tools such as knives, chisels, scissors, etc. A tool grinder may be a solid wheel of abrasive, or it may be a belt grinder.