The Triumph Twist Drill Co. Wire Gauge Drill Bit in size 20J features a precise 0.1610 inch diameter with standard jobber length design for versatile drilling applications.Triumph Twist Drill Co. Wire Gauge Drill BitWire gauge size 20J specification0.1610 inches (4.09mm) diameterJobber length for standard drilling depthProfessional grade constructionIdeal for precision drilling in metal wood and other materials where exact hole size is critical. The jobber length provides excellent balance between drilling depth capability and bit strength.