Lay is the direction of the predominant surface pattern, ordinarily determined by the production method used.

Normal profile is the contour of a surface in a plane perpendicular to the surface, unless some other angle is specified

One micrometer is equal to one thousandth of a millimeter.

Flaws are irregularities, which occur at one place or at relatively frequent or widely varying intervals in a surface

Checking vertical alignment only

Checking horizontal alignment only

Checking angular alignment only

Checking vertical and horizontal alignment

Enamelling

Painting

Oxidation

Polishing

Lapping

Fixing

Charging

Rubbing

To retain lapping paste

To reduce friction

To collect cutting chips

To prevent distortion of the lapping plate