August 13, 2024 shank 1 Sq. 1 1/2 Shank Lathe Turning Tool Post Holder Modular Tooling Adapter 1.0 Please review all pictures. Slot Width : Made for 1″ Square tool holders, slot measures about 1.2″. Shank Diameter : 1 1/2. Please offer on multiple items to get the best deals!