Resisting wear and fractures when cutting hardened steel, these cubic boron nitride inserts last longer than carbide inserts. Use them for high-speed finishing and interrupted cutting applications. All have multiple cutting edges, so when an edge dulls, rotate the insert in your holder to use a sharp edge. Those with larger nose angles and tip radii have stronger cutting edges, but create more vibration and a rougher finish.

For traceability, inserts come factory sealed from the manufacturer.

These inserts are made with a black ceramic alumina on the cutting edges. Compared to carbide inserts, ceramic lasts longer in hardened-steel and cast iron tooling applications because it is chemically inert and has better heat resistance. Ceramic inserts have comparable wear resistance to cubic boron nitride, but ceramic is best for continuous and light cutting while cubic boron nitride can also be used in heavy interruption. These inserts have multiple cutting edges, so when a cutting edge becomes dull, rotate the insert in the holder to use a sharp edge. Larger nose angles and larger tip radii provide a stronger cutting edge but result in increased vibration and a rougher finish.

Made from heat-resistant ceramic, these inserts are reinforced with strands of silicon carbide to add strength and prevent chips or fractures. Also called whisker ceramic inserts, they last up to four times longer than carbide inserts when cutting nickel- or cobalt-based superalloys. Designed for semi-interrupted cutting, they're often used to machine imperfectly round workpieces, such as a shaft with a keyway. They’re tough enough for roughing, or quick material removal, but you can also use them for medium cutting and finishing.

These negative-rake inserts are the first choice for most turning applications. They have cutting edges on both sides, so you can flip them over when the edges on one face wear out. Since they have a 0° lead angle, or neutral cut direction, they can cut from either right to left or left to right.

Inserts with a larger tip radius remove more material with each pass but cut less precisely than smaller inserts. Select the insert with the largest tip radius that still turns your workpiece to the desired shape.