Secondary Operations

SECONDARY OPERATION	TYPICAL PARTS	OBJECTIVES
REPRESSING
Coining	All	Densification, dimensional control.
Sizing	All	Dimensional control.
IMPREGNATION
Oil	Bearings	Make bearings self-lubricating.
Resin	Structural	Improve machinability. Prepare surface for plating with other metals. Seal parts gas or liquid tight.
INFILTRATION
Infiltration	Ferrous Structural	Improve strength up to three times. Seal parts gas or liquid tight. Prepare surface for plating with other metals. Improve ductility and machinability.
HEAT TREATING
Quench and Temper	Ferrous Structural	Improve strength and hardness.
Steam Treat	Ferrous	Make surface hard and wear resistant. Improve corrosion resistance and seal porosity.
MACHINING
Drill and Tap	All	To install set or assembly screws.
Turning	All	Machine to exact tolerances. Form undercuts not possible with punch and die tooling.
Milling	All	Form undercuts or slots
Grinding	All	Remove stock; make faces parallel; improve surface finish and tolerances
FINISHING
Deburring	All	Remove sharp edges related to punch and die tooling
Burnishing	Ferrous Structural	Ball size, roller burnish for size control and surface finish.
Coating Oil Dip	Ferrous	Corrosion resistance.
Copper, Nickel, Cadmium, Zinc, Chromium Plating	Ferrous	Corrosion resistance, appearance
Welding	Ferrous, 6.8g/cm min. density	Makes assemblies from two or more parts
Black Oxide	Ferrous, resin impregnated	Corrosion resistance, paint base
Mechanical Surface Treatments: Glass Beading, Wire Brush, Sanding	All	Clean, improve surfaces
Tumbling/Vibratory Finishing, Shot Peening	Ferrous, Forgings	Improve surface fatigue life.