Back Home / Cutting Tools / Drill Bits / DRILL BIT-HEAVY DUTY JOBBER LENGTH, 5/16″ DRILL BIT-HEAVY DUTY JOBBER LENGTH, 5/16″ SKU: TID516 Categories: Cutting Tools, Drill Bits Diameter of 5/16″. Jobber length, 4-1/2″. 135° split point. Black oxide finish. Heavy duty construction. Recommended for portable drilling of low to medium carbon steels, cast iron and wood. Diameter of 5/16″. Jobber length, 4-1/2″. 135° split point. Black oxide finish. Heavy duty construction. Recommended for portable drilling of low to me Case Quantity: 6 Log In For Pricing