Pistol grinders feature double front spindle bearings to provide for thrust as well as radial loads. Rustproof liner and end plates prevent moist air from corroding vital motor surfaces. Built-in lubricator with large oil reservoir assures continuous motor lubrication. "Heavy duty" grinders have spindle and motor housings of light weight steel tube construction which can take rough handling and resist wear and tear. The constant speed governor holds the wheel at the most efficient cutting speed from no load to full load and eliminates danger of overspeed when running free.