Honing

(in metalworking), the final processing of parts in order to produce precise dimensions (first class and higher) and a smooth surface, corresponding to the tenth to 14th classes, as well as the lapping of one part to another.

Honing is performed manually or on honing machines with a lapping tool, using abrasive powders or pastes. In lapping and manual honing of parts that are used as a pair (for example, a valve and the valve seat), the part itself is used as the lapping tool, and the abrasive powder or paste is applied to its surface. Honing may also be done on honing plates, whose surfaces are saturated with the abrasive powder or paste. Honing involves repeated movement of the part along the honing plate, of the lapping tool over the part, or of one part against the other.

Honing is used in manufacturing precision measuring tools and fuel and hydraulic equipment.

in machine building, a finishing operation, primarily for the internal cylindrical surfaces of parts, that uses a fine-grain abrasive tool in the form of rods, or sticks, mounted on a honing head, or hone. The abrasive rods are pressed against the surface being machined, and the honing head, which is attached to the spindle of a honing machine, performs rotational and reciprocating motions. Hardened gear wheels are honed with a honing head in the form of a helical slotter ram that meshes with the gear wheel being machined and performs rotational and vibrational motions simultaneously. Honing is one of the last operations performed on a part; it follows boring, broaching, reaming, or grinding. Honing results in a machine precision up to class 1 and a surface roughness up to class 13.