Common Industry Terms

TIR (True Indicated Radius)

A measurement of how close to a perfect circle a roll face is. Typically measured in thousandths of an inch: 0.001”.

Concentricity

This term refers to the measurement of the distance between the center of rotation of the bearing area and the center of rotation of the roll face. Usually measured in thousandths of an inch; 0.001”.

Surface Roughness (Ra)

Measurement of the average peak to valley distance occurring on the roll surface. Measured in microinches, millionths of an inch.

STR (Straightness)

This is defined as the deviation from a specific shape which is measured by the distance between two parallel lines. Also referred to as taper. Typically measured in thousandths of an inch; 0.001”.

Residual Chrome Thickness

Amount of chromium remaining after final grinding. Thickness will vary with finish.

Gloss

A measurement of the amount of light from a standard source reflected by a surface. Typically measured in gloss units as defined by ASTM standards, commonly referred to as Percent Gloss.