K3 Chuck Key for use with Jacobs, 3, 3A, 3B, 3PD, 14N, 34, 34B, 34KD, 634, 58B. Bisco Tool Supply will help you figure which key is right for your Jacobs Drill Chuck. Call the sales staff at Bisco Toll Free 1-866-247-2635 with any Drill Chuck Questions. Wholesale Drill Chucks are also available.