Sunnen L4-NM45 Abrasive Stone for Precision Honing

Sunnen L4-NM45 is a Cubic Boron Nitride (CBN) honing stone in Sunnen’s L4 Series, specified at 150 grit. Engineered for precision bore finishing, this stone delivers fine material removal and a smooth bore surface when used with Sunnen L4-series honing tools. The NM45 designation identifies it as part of Sunnen's standardized L4 family, enabling repeatable wear characteristics and consistent bore sizing through successive honing passes. As a CBN, the abrasive provides high hardness and wear resistance appropriate for finishing applications on a range of metals, helping achieve tight tolerances and refined surface textures. The L4 stones are designed to pair with Sunnen honing units and abrasives in the L4 family to support precise bore sizing and reproducible finishes. This 150-grit configuration is well suited for finishing steps that require finer surface texture without removing excessive material. Typical applications include final honing passes where tight tolerances and smooth internal surfaces are required, such as automotive engine bores, hydraulic components, and precision cylindrical bores, all within the context of Sunnen's precision honing ecosystem. Because it is part of Sunnen's NM-series within the L4 lineup, it is intended to deliver stable performance under standard honing parameters, with predictable wear and consistent sizing across cycles.