Thread Mill for Hardened Steel

A mold-making shop recently approached us with broken taps embedded in pre-hardened tooling blocks. Tapping seemed economical for the initial low-volume run, but rapid tool wear quickly caused rough surface finishes, torn pitches, and catastrophic tool failure. When a tap breaks inside an expensive cavity, EDM burning is often the only extraction method, inflating production

A client recently brought us a difficult threading job involving heat-treated SKD11 tool steel hardened to HRC62. Standard taps chipped and snapped almost immediately, while general-purpose carbide end mills suffered severe flank wear and left heavy chatter marks. In high-hardness machining, these failures stall production and quickly drive up scrap rates. When workpiece hardness exceeds