Angle grinders and bench grinders are common tools with significant hazards. Abrasive grinding wheels rotate at high speeds and can disintegrate if not properly maintained. Wheel guards must cover all but the bottom area where work is performed. Guards must protect against flying wheel fragments. Work rests must be positioned close to the wheel surface (typically 1/8 inch) to prevent work from being caught and thrown. A rotating wheel can catch a workpiece and accelerate it to dangerous speeds. Operator positioning must keep the operator to the side of the wheel path in case the wheel disintegrates and fragments fly outward. Direct face-on positioning in front of the wheel creates maximum hazard. Personal protective equipment must include face shields or full-face protection in addition to safety glasses. Safety glasses alone do not provide adequate protection against high-speed fragments. Hearing protection must be worn due to high noise levels from grinding. Wheels must be visually inspected for cracks before operation. Defective wheels must not be used. Wheels that have been dropped or impacted must be discarded. Wheel balancing before operation reduces vibration and extends wheel life. Proper speed rating must match the equipment specification. Using wheels rated for higher speeds than the grinder speed is important; using lower-speed wheels risks wheel failure. Training on safe operation and hazard recognition must be provided before use.