Dorian Tool E05K-SCLPL-1.8, 5/16" Diameter Carbide Boring Bar, Thru Coolant, Left Hand, With -5-Degree Lead Angle, For CP_-1.81.2_ Inserts, With 0.335" Minimum Bore and 5" Overall Length, MPN: 59632, 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