"Inconel 800" and "Incoloy 800" refer to the same UNS N08800 material — an iron-nickel-chromium alloy that, in various eras and regions, has been sold under both trademarks by the alloy's original developer. The alloy's current producer, Special Metals Corporation, standardizes on the name INCOLOY alloy 800, and that is the designation you will see on current mill certifications and technical bulletins. "Inconel 800" persists in some older literature, distributor catalogs, and regional usage, but it is not a chemically distinct grade — sourcing either name against UNS N08800 gets you the identical alloy.

Chemically, this is the baseline 800-series iron-nickel-chromium superalloy: roughly equal parts nickel and iron balanced against 19-23% chromium, with small aluminum and titanium additions for a modest strength boost. Its iron content keeps it more cost-effective than a solid nickel-base superalloy while still delivering strong resistance to oxidation and carburization at elevated temperature. It is a common choice for furnace muffles, radiant tubes, heat-treating fixtures, and other equipment that runs hot but doesn't require the tighter creep control of the 800H/800HT variants, and it is normally supplied and used in the annealed condition.

Nickel-iron-chromium superalloys like this one are demanding to machine for a consistent set of reasons: low thermal conductivity concentrates the heat generated by the cut right at the tool edge instead of carrying it away in the chip, the alloy work-hardens noticeably wherever a previous pass rubbed instead of cut, and it holds onto its strength at elevated temperature rather than softening the way steel does as the cutting zone heats up. Together these push cutting forces, edge temperature, and abrasive wear well above what a similarly hard steel would produce.

The alloy's substantial iron content dilutes the tough nickel-chromium matrix that makes solid nickel-base alloys like Inconel 625 or Hastelloy so punishing on tooling, so it machines somewhat more forgivingly than those true nickel-base grades even though it remains firmly in the "difficult" category. Chips tend to be tough and stringy rather than brittle, so chip control and evacuation deserve real attention alongside tool wear.

A rigid setup is essential — any flex or vibration burnishes the surface and work-hardens it before the next pass. Use sharp, positive-rake carbide with a coating built for heat-resistant alloys, run at moderate-to-low cutting speeds, and keep feed rates high enough that the edge consistently cuts beneath the hardened layer left by the prior pass instead of skating across it.