ALUMINUM GLOSSARY - N

Natural Aging

See Aging .

Nesting Joints

A general class of joints with mating elements that serve to align adjoining parts with little or no self-locking action.

Nitriding

The introduction of nitrogen into the surface of tool steels by holding at a suitable temperature in contact with a nitrogenous material, usually ammonia, to produce a hard wear resistant case.

Nitrogen Shrouding

The process of injecting nitrogen, either liquid or gaseous, at the die openings to surround the emerging extrusion in an environment high in nitrogen and low in oxygen. This delays the formation of oxides on the exit edge of the die bearing providing a superior surface finish on the extrusion.

Nonferrous

Not containing iron; a generic term for metals other than iron and alloys not containing iron.

Nonfill

Failure of metal to fill a forging die impression.

Non-Heat Treatable Alloys

Aluminum alloys that are strengthened by cold working and not by heat treatment.

Notch Double Shear

An abrupt deviation from straight on a sheared edge. This offset may occur if the flat sheet or plate product is longer than the blade for the final shearing operation.