Inconel 702 (UNS N07702) is a nickel-chromium-aluminum superalloy that takes a different path to high-temperature strength than most of its Inconel siblings: instead of leaning primarily on titanium and niobium for precipitation hardening, it uses a comparatively high aluminum content (roughly 2.75–3.75%) to form a fine strengthening phase, while that same aluminum also builds a dense, adherent alumina scale on the surface at elevated temperature. That dual role gives 702 both good mechanical strength after aging and strong resistance to oxidizing atmospheres at very high temperatures, a combination that makes it well suited to gas turbine hardware, high-temperature fasteners, and furnace components that see sustained heat exposure.

Because strengthening comes primarily from aluminum rather than titanium, 702 is less commonly used than 718 or X-750 in structural aerospace applications, but it remains a solid choice wherever oxidation resistance at very high temperature matters more than ultimate tensile strength. It is normally supplied and machined in the solution-annealed or aged condition depending on the target application, and — like other age-hardened nickel alloys — it machines noticeably harder once aged than in the softer annealed state.

Machining Inconel 702 follows the same general pattern as other age-hardened nickel-based superalloys, with the added twist that its strengthening phase is built around aluminum rather than titanium or niobium. In the aged condition, the alloy resists deformation and retains hardness well into the cutting temperature range, which keeps forces and heat generation elevated throughout the cut compared with a plain stainless steel of similar appearance.

Work hardening is a constant concern — any rubbing, hesitation, or light finishing pass burnishes the surface and creates a hardened skin that fights the next cut. Low thermal conductivity typical of nickel alloys concentrates heat at the tool edge instead of carrying it into the chip, driving flank wear and notching at the depth-of-cut line if speeds run too high. The alumina-forming aluminum content also contributes to abrasive wear on the cutting edge over extended runs.

A rigid, vibration-free setup with sharp, positive-rake carbide is essential, along with cutting speeds toward the moderate-low end of the nickel-alloy range and feed rates high enough that each pass consistently cuts beneath the hardened layer left by the one before it. A hard substrate with a thin, wear-resistant coating generally outperforms tougher general-purpose grades at this hardness level.