OD
Outside diameter (of a coil).

Off Gauge
A defect referring to a variation of offset of the thickness of the plate from the designated aim gauge thickness and tolerance.

Offsetting
A coating defect consisting of a transference of smearing of ink or coating or other substance from the surface of one sheet of coated substrate to the back of the next sheet in a stack.

Oil Film Weight
Measure of the amount of oil applied to a flat rolled steel product; for Tin Mill Products, the measure is grams/base box; for Sheet Products, the measure is oz./sq.ft. (or gm./sq.m.).

Oiled
A product to which oil has been applied to retard rusting.

Oiling
The application of a surface layer of lubricant intended to retard rusting on sheet products and lubrication on Tin Mill products.

Olsen (Tester)
A device used to indicate the draw quality of the steel and to detect breakage caused by contamination or peeling of the zinc coating.

Open Line
Usually a steel-making defect, an open line refers to a line down the length of the strip caused by unknown conditions.

Ore
An iron bearing material used primarily in the blast furnace.

Organosol
Organosols contain poly-vinyl chloride (PVC) dispersed in solvents. At temperatures of 325-350° F (165-175° Centegrade) the vinyl particles coalesce and dissolve in the plasticizers to form homogeneous films with good hardness, toughness and adhesion.

Overpickled
Reject caused by the strip laying in acid for a period of time.

Overwidth
Product whose width is above the customer’s finished width tolerance.

Oxidation
Rust, corrosion. See Red Rust and White Rust.