Unleash the full potential of your machining with Winona Van Norman's CBN Inserts. Engineered with Cubic Boron Nitride—the second hardest material on earth—these inserts are designed to excel where traditional tools fail. Our double-sided, 1/2" round CBN inserts provide unmatched durability and precision for vertical milling and boring applications, particularly on hardened materials. The unique geometry and exceptional edge strength ensure a smooth, chatter-free cutting action, allowing for incredibly high feed rates and a superior surface finish. Ideal for aggressive roughing, precise profiling, and critical tasks like engine head and block resurfacing, our CBN inserts offer a cost-effective solution for maximizing productivity and achieving the cleanest, most accurate finish on the market. CBN Insert, 1/2" Round, 3/16" Thick, Double Sided, T-Land Chamfered Edge 10 Deg. 0.005" (CBN - Cubic Boron Nitride - SUPERABRASIVE). For engine block and head surfacing, Vertical Milling and Boring.