Machining apparatus

A machining apparatus, comprising:

• an insert largely in the form of a plate having a mount portion with a plurality of sides lying on the sides of an imaginary polygon having an axis, said sides forming locating sides, said insert having a plurality of arms projecting radially outwardly at the corners of said imaginary polygon, each arm having a substantially radially extending arm side with a radially inner end merging with one of said locating sides and with a radially outer end, said arm forming a cutting edge lying at said radially outer end of said arm side;
• a tool holder apparatus which includes a pair of flat positioning surfaces constructed to bear against a pair of said insert locating sides, and a cutout lying between said positioning surfaces for receiving one of said arms, said cutout being large enough that it does not engage any portion of an arm lying therein, said tool holder apparatus including means for pressing an insert locating side against said one of said positioning surfaces.

In a machining apparatus which includes a pocket member that can mount on a holder and that can hold a cutting insert which forms a cutting edge for machining a workpiece, wherein said pocket member has a first flat pocket face surface for mounting facewise against a flat holder surface of said holder, and said pocket member has a second flat pocket face surface against which can be mounted a flat orienting face surface of said insert, the improvement wherein:

• said second flat pocket face surface is angled by at least one degree, but not more than about ten degrees, from parallelism with said first flat pocket face surface.