Style SGTHR 19-5 Cut-Off Tool Holder-Gtn-3 (2203-1950) ~ Shank size is 3/4 X 1/2". ~ Insert width is .187 & .200". ~ Use with GTN-5 inserts which are not included. ~ Maximum work diameter is 1.38". ~ T-Cut style is the original self-grip. ~ High reliability, rigidity and stability. ~ Superior straightness of cut.