Kennametal Beyond Shield combines three point clamping with super hard PCBN grades for cast iron machining
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Kennametal's Beyond Shield three-point clamp design applies clamping force towards the front of the insert, closer to the cutting edge. This can significantly reduce vibrations that may lead to cracking and failure. The carbide-clad clamp also resists wear from the constant bombardment of chips associated with cast iron machining.
KBK35 grade inserts are designed to handle intrinsically tough cast iron. The material presents a number of machining challenges for cutting tools, says Kennametal. Casting quality can be unpredictable, low sulphur content can decrease tool life by as much as 60% and increased ferrite content can lead to high chemical wear – also substantially decreasing tool life.
KBK35 grade, with a 'multi modal' PCBN structure, has a higher than usual cubic boron nitride content for increased wear resistance and longer insert life in both rough and finishing operations. A CVD coating provides protection against chemical wear and post-coat treatments improve cutting edge toughness.
While KBK35 performs well in both aged and unaged cast iron – and in some cases like brake drums, is capable of producing many times the number of parts possible with ceramic-based alternatives – Kennametal also offers KB1340 grade for aged cast iron. On brake disc field tests, says the company, KB1340 produced 1,700 parts compared to the 1,500 parts produced by a PCBN insert.
