S05 SCLCR06 Mini Indexable Boring Bar ~ Shank size is 5/16". ~ Minimum bore is .315". ~ Overall length is 4". ~ Neck diameter is .236". ~ Neck length is .985". ~ Suitable inserts are CCMT-21.5. ~ The insert screw is M2.5 X 6 (#2100-0070). ~ Torx wrench is a T-8 (#2100-0092).