a machine for sharpening metal-cutting tools. A distinction is made between tool grinders with abrasive and nonabrasive grinding; machines with abrasive grinding are the more common type. They include simple grindstone sharpeners; special lathes for cutting tools, drills, broaches, dies, and certain gear-cutting tools; and all-purpose machines for multiblade tools (milling cutters, countersinks, reamers, and tap borers).
The tool used for abrasive grinding is an abrasive grinding wheel. Tool grinders may be equipped with one or two grinding wheels. Grinders for cutting tools usually have a movable slide rest, which holds the cutting tool for grinding, or a grinding headstock, which moves relative to the slide rest; the machine is equipped with a scale for setting the cutting tool at the required angle. Grinders for drilling tools are equipped with devices for producing predetermined grinding angles. All-purpose grinders have headstocks between whose centers various types of tools may be held for grinding. The table of an all-purpose tool grinder moves back and forth relative to the rotating grinding wheel.
Nonabrasive tool grinders may be of the anode-mechanical electric-spark and ultrasonic types. After grinding, a tool undergoes finishing (lapping).
D. L. IUDIN