Toolholder anvil seat for indexable inserts

In a toolholder combination for use with pellet type, polygonally shaped, throwaway cutting inserts which includes a removable anvil seat secured to the holder body having a recess to receive a cutting insert, that improvement which comprises:

• (a) a circular pocket having a first diameter formed in said toolholder body and having a flat base surface and straight enclosing walls parallel to the axis of the pocket and a concentric circular well having a diameter less than said first diameter formed in said base surface within the walls of said pocket below said base surface,
• (b) an anvil seat disposed on said toolholder having an insert recess in the top thereof and having first circular outer walls complemental to and interfitting with said enclosing walls of said circular pocket, an annular base surface to seat on said flat base surface of said pocket, and a circular depending projecting below said annular base surface to insert into and interfit into said well to positively and selectively locate said seat on said toolholder at a desired lead angle,
• (c) means to locate the desired orientation of said anvil seat in said well, and
• (d) means to locate and retain said anvil seat in the desired orientation on said toolholder in conjunction with said last named means to maintain the desired orientation of said anvil seat comprising a screw on an axis concentric with that of said circular pocket having a head countersunk into the bottom of said insert recess and a threaded shank extending into said toolholder body through said circular depending projection.