Dorian Tool E08K-STUPL-2, 1/2" Diameter Carbide Boring Bar, Thru Coolant, Left Hand, With -3-Degree Lead Angle, For TP_-21.5_ Inserts, With 0.587" Minimum Bore and 5" Overall Length, MPN: 59788, Features 6xDiameter Boring Ratio (8xDiameter under favorable conditions), Thru-Coolant, 1/2 (12mm) or larger bars have threaded ends for easy coolant connection, Precision ground solid carbide body for high rigidity in deep hole boring, Brazed head is heat treated to 40-44HRC and precision machined to accept standard inserts