Inconel 722 is an age-hardenable nickel-chromium-iron superalloy that sits alongside the better-known X-750 in the same broad family of precipitation-strengthened Ni-Cr wrought alloys. Its strength comes from a gamma-prime phase built primarily around titanium and aluminum, developed through a solution anneal followed by an aging treatment. Unlike X-750, alloy 722 doesn't rely on a niobium addition for its strengthening response, which gives it a somewhat simpler precipitation chemistry while still delivering a useful combination of elevated-temperature strength, good corrosion resistance, and resistance to relaxation under sustained load.

Because it work-hardens readily and responds well to precipitation heat treatment, 722 has historically been used for springs, fasteners, and structural components that need to hold their strength and dimensional stability at moderately elevated service temperatures. Shops most often see it in the aged, high-strength condition rather than as soft annealed stock, since that's the condition in which it delivers the mechanical properties it's specified for.

As one of the earlier age-hardenable nickel-chromium alloys developed alongside the X-750 family, 722 remains a useful reference point for understanding how titanium and aluminum content drive the strengthening behavior common across this whole alloy group.

Inconel 722 machines with the same underlying challenges found across the whole age-hardenable Ni-Cr-Fe family: low thermal conductivity that traps heat at the cutting edge instead of carrying it away in the chip, a strong tendency to work-harden the surface left behind by each pass, and a microstructure that keeps much of its strength right at the elevated temperatures generated during cutting. In the aged, high-strength condition that shops typically encounter, cutting forces and edge temperatures run noticeably higher than on plain carbon or low-alloy steels of similar hardness.

Because the alloy work-hardens so readily, dwelling on a cut, using a dull edge, or taking very light finishing passes all risk leaving a hardened skin that's harder to machine on the next pass than the bulk material underneath. Chips also tend to be tough and continuous, and can gall or smear onto the rake face under heat and pressure if the tool geometry and coating aren't matched to the material.

A rigid setup, sharp positive-rake cutting edges, and a steady, adequate feed rate that keeps the tool engaged and cutting — rather than rubbing — are the best defense against both work hardening and premature edge wear. Coated carbide grades with good hot hardness generally outperform uncoated tooling once the material is in its aged condition.