Common Use: Ideal for locking and unlocking the drill bit and keeping the drill bit securely in place. 8mm Dia Pilot T Shaped Handle 21mm Gear Teeth Dril... – Grandado Carbon Steel Chuck Key 21.4mm Gear Barnwell K3 Chuck Key With Thumb Rest To Fit Jacobs 3, 34 & 35 Series Chuck Keys For Drill CONSTRUCTION: Made from solid carbon steel with chrome coating. Common Use: Ideal for locking and unlocking the drill bit and keeping the drill bit securely in place CONSTRUCTION: Made from solid carbon steel with chrome coating. 13.93 $16.99 Free shipping Chuck Key 8mm 11 Teeth Hammer Drill Tighten Tool for 3-16mm Drill Chuck $14.27 $17.40 Free shipping Compatible with 3, 3A, 3AE, 3B, 3KD, 3PD, 6AE, 6A-2A, 6A-33, 6B, 14N, 34, 34B, 34KD, 34PD, 35, 55B, 56B, 58B, 75A, 634, 634B44Z-6B and 43SB-6A., ., ., Dimensions:This is a Chuck Key with a thumb rest., 8mm Pilot 11T 21., 3mm Gear Diameter.