Aloris ATB Series threading bars can be used for internal right or left-hand threading. Available in five sizes, these bars accommodate standard triangular-shaped throwaway threading inserts in a hardened seat. 

The ATB Series shank has three flat sides specially designed for use in Aloris boring bar holders #1, #2, #13, #4 and # 41. They may also be used in any Aloris boring bar holder.
Excellent for CNC machines.

Dimensions (see image):
A: 1⁷/₁₆"; B: 3¹/₈"; C: 1¹/₄"; D: 1¹/₂"; L: 14"; I.C.: ¹/₂"

Replacement Parts:
Insert Screw ASA4T
Key T20
Shim YE4(LH)