Tool holder for a screw machine box tool

A small diameter screw machine box tool, comprising;

• a housing with a through bore for work travel on an axis and a tool holder clamp on the housing offset from the through bore with a clamp opening generally transverse to the through bore and the work, an elongated tool holder having a longitudinal axis, adapted to fit in the clamp opening and be clamped to the housing, a polygonal insert recess on a working end of the tool holder lying on a plane generally transverse to the holder axis, a carbide insert having multiple cutting edges mounted in the recess generally transverse to the longitudinal axis of the tool holder, said insert having at least two adjacent, opposed, and identical cutting surfaces, said recess and insert being constructed and mounted so that the opposed identical cutting surfaces on the insert overhang opposite sides of the tool holder in mirror image fashion whereby the tool holder can be used in both right and left hand box tools without indexing the carbide insert, the tool holder having a generally transverse end surface at its working end having an angle of approximately 98 degrees with respect to the longitudinal axis of the tool, said insert recess lying in said end surface, said recess being generally an equilateral triangle open at one side to one side of the total holder to expose the two cutting surfaces of the carbide insert for working engagement with the work.

A tool holder for left and right hand small diameter screw machine box tools of the type having a housing with a through bore for work travel on an axis and a tool holder clamp on the housing offset from the through bore with a clamp opening generally tranverse to the through bore and the work, comprising:

• an elongated tool holder having a longitudinal axis, adapted to fit in the clamp opening and be clamped to the housing, a polygonal insert recess on a working end of the tool holder lying in a plane generally transverse to the holder axis, a carbide insert having multiple cutting edges mounted in the recess generally transverse to the longitudinal axis of the tool holder, said insert having at least two adjacent, opposed, and identical cutting surfaces, said tool holder having a substantially uniform diameter whereby the tool holder can be easily inserted and removed from the clamp without substantially loosening or removing the clamp, said recess and insert being constructed and mounted so that the opposed identical cutting surfaces on the insert overhang opposite sides of the tool holder in mirror image fashion whereby the tool holder can be used in both right and left hand box tools without indexing the carbide insert, the tool holder having a generally transverse end surface at its working end having an angle of approximately 98 degrees with respect to the longitudinal axis of the tool, said insert recess lying in said end surface, said recess being generally an equilateral triangle open at one side to one side of the tool holder to expose two cutting edges of the carbide insert for working engagement with the workpiece.