A professional who laps metal objects, such as gauges and machine parts, to specifications within tolerances as fine as 0.00001 inch, applying knowledge of abrasives and lapping procedures. Responsibilities include:

• Measures workpiece with instrument, such as optical comparator, compares workpiece dimensions with specifications to ascertain amount of stock to be removed, and estimates number of lapping strokes required.
• Mounts workpiece in fixture, or in power-driven mechanism, using wrenches and keys, and positions work aids, such as parallel bars and rods to guide motion of lap i or workpiece.
• Files grooves in surface of lap to hold lapping compound. Applies compound to workpiece and rubs lap across workpiece with rotary or reciprocating motion, feeling friction and applying required pressure based on previous experience, to attain specified tolerance.
• Measures workpiece to verify conformance to specifications, using special gauges.
• Straightens or polishes rods by inserting and pressing them between two rollers with lapping compound.