P
Passes
This refers to a term given to the number of times the cut needs to be carried out.
PN edge type
A cutting edge configuration in which the axial rake angle is negative and the radial rake angle is positive. This type of configuration is not put into practical use as the cutting edge is not sharp and chip evacuation is poor.
Polycrystalline compacts (sintered super-hardened compacts)
Polycrystalline compacts is a term that refers to CBN and PCD tool grades. These tool grades are manufactured by adding metal or ceramic powders to powders of an ultra-hard cutting tool material like PCB and CBN. Once they have been added together the tool grade is sintered under high temperature and high-pressure conditions.
R
Rake angle
The rake angle is the angle between a line perpendicular to the machined surface and the rake face.
Reaming
A process that is used to finish machine a pre-drilled hole.
Removing scale
Removing the surface of a casting or a hot rolled work piece. Scale is a black substance due to the sand of a sand mould, or an oxidizing film.
Positive land
The land of the cutting edge is not flat, it is given a slight angle to that makes it positive.
Power
This term refers to the power needed to make machining possible.
Pull stud
A stud that is screwed into back end of a BT shank holder. When the holder is inserted into the spindle this pull stub is gripped and pulled upwards thus securely locating the holder.
PVD-coated carbide
A carbide that has been coated using physical vapor deposition coating method.
Rigidity
The term rigidity refers to the ability of a material to withstand bending or twisting.
Roller bearing
A device that comprises of rollers that are housed inside a bearing. It is used to reduce the friction between 2 rotating components.