PCBN Cubic Boron Nitride Insert for Hardened Steel and Cast Iron High Speed Cutting Indexable Insert

PCBN tooling for hardened steel is a game-changer, but only if the edge is sharp out of the box. This one is sharp. We ran it on 4140 pre-hardened at HRC58 and got a 0.8 mm DOC at 0.15 mm/rev feed with no break-in. Tool life at HRC62 in D2 was north of 220 parts on a finishing pass. Better wear-pattern than our old Mitsubishi BC-series. Honest review: it is pricier than Sandvik, but the edge geometry is superior and the brazed joint is holding up.

For hard turning D2 at HRC60-62, these PCBN inserts are about as good as it gets. We did 180 parts per corner at 150 m/min, 0.12 mm/rev, no coolant. Surface finish was a consistent Ra 0.4 mirror across the campaign. We tried several Asian-sourced PCBN brands before — none gave us this kind of consistency. Holds edge well, no notch wear at the DOC line. Highly recommended.

Pricey but priced right for what you get. PCBN inserts in the right grade for our application (continuous cut on hardened bearing steel). Cutter inserts cleanly, no chatter, no BUE. We have burned through 4 corners and the wear is barely measurable. Reground edge geometry is consistent with the new one. This is a properly spec'd PCBN, not a relabeled ceramic insert.

Cutting HRC62 D2 tool steel die details — finish pass at 0.2 mm/rev, 0.05 mm DOC, dry, and got plus-minus 0.008 mm on the first article. CBN grade selection was clearly the right call for our material. The cermet binder looks intact under microscope. We previously had a Brazilian brand fail catastrophically after 20 parts — this one is at 160 parts and counting with no measurable wear. Great value at this grade.

Welded-on PCBN form tool for a small custom geometry (radius form on an automotive valve seat). Got the drawing, sent it to the seller, got the tool in 12 days. Edge held up at 200 m/min cutting on HRC60 8620 steel — about 850 parts between dress cycles. Way better than the carbide form tool we had been using (which lasted 50 parts). Sold us on PCBN for hard turning from now on.