Sunnen BL12385AS Soft Steel Mandrel 5.375 Inch Shank L Series

Sunnen BL12385AS Soft Steel Mandrel is a 5.375-inch shank, L-Series mandrel from Sunnen’s BL12 soft-steel family, engineered for high-precision honing of small-to-mid bore diameters. It uses an L12 stone and provides an abrasive length of 3.5 inches, with a bore range of 0.400–0.416 inches; this combination supports consistent bore geometry and surface finish. The tool features a shank length of 5.375 inches and a reach length of 5.375 inches, enabling access to deeper bores when mounted in Sunnen honing machines. Built for durability, it delivers repeatable results in automotive, aerospace, and general manufacturing applications that require tight tolerances, and it’s designed to work with Sunnen L-Series tooling and soft-steel shoes for reliable alignment and interchange with compatible mandrels.