Taiki 8" Tongue & Groove Steel Soft Jaws - 3 Piece Set ~ Supplies maximum concentricity on finish turning operations. ~ Can be bored or turned to fit work piece. ~ Jaws can be hardened. ~ Chuck size is 8". ~ Groove width is 0. 313". ~ Tongue width is 1/2". ~ Screw size is 3/8". ~ Hole space is 1. 75". ~ Tongue to front is 1. 329". ~ Tongue position is offset. ~ Width is 1-1/4". ~ Length is 3-3/4". ~ Height is 1-1/4". ~ For use on Buck, Bison, Cushman, Huron, PBA, Yuasa and Rohm Chucks. Taiki # PSJ07-8032B