5/8" JT3 Drill Chuck With 3/4" Straight Shank Arbor The drill chuck is a 1/8-5/8" JT3 drill chuck with key. This drill chuck is accurate and has strong gripping force. It is used with portable, bench or floor type drill presses. The arbor is a 3/4" straight shank to JT3 drill chuck arbor. The arbor is also hardened and ground.