This alloy belongs to the high-strength family of titanium grades developed for thick-section aerospace structure, where standard Ti-6Al-4V doesn't have enough hardenability to reach full strength all the way through a heavy forging or plate. Industry literature most commonly documents this composition as Ti-6Al-2Sn-2Zr-2Mo-2Cr-0.2Si, widely known by its shorthand "Ti-6-22-22" — six alpha/neutral stabilizing elements (aluminum, tin, zirconium) balanced against roughly 4% combined beta stabilizers (molybdenum and chromium), with a small silicon addition to support elevated-temperature stability. The composition and cutting data below reflect this verified, industry-documented alloy.

Developed by RMI Titanium in the early 1970s, this grade was engineered specifically to out-hardenable Ti-6Al-4V: its heavier beta-stabilizer load lets it respond to heat treatment in section thicknesses where Grade 5 would air-cool too fast to develop full strength. The payoff is a titanium alloy that can match or exceed Ti-6Al-4V's tensile strength deep inside a thick forging, while still holding onto useful strength and creep resistance at moderately elevated service temperatures. That combination makes it a natural fit for landing gear components, thick structural fittings, and high-strength fasteners where both section size and elevated-temperature stability matter.

This alloy machines like a tougher cousin of Ti-6Al-4V. It shares titanium's core machining challenges — low thermal conductivity that concentrates heat at the cutting edge instead of carrying it off in the chip, and a chemical reactivity with tool materials that accelerates diffusion wear once temperatures climb. But the extra beta-stabilizer content that gives this grade its deep-hardening strength also raises its hot strength and work-hardening tendency compared to standard Grade 5, so it holds its resistance to cutting forces at temperatures where Ti-6Al-4V would start to soften.

In practice that means running noticeably slower cutting speeds than you would on Grade 5, while still keeping feed rates firm enough to cut cleanly under any work-hardened layer left by the previous pass. Rigidity matters even more here — this alloy's higher strength means higher cutting forces at a given depth of cut, so any flex in the workholding or tool overhang shows up quickly as chatter or premature edge wear. Flood coolant is essential to pull heat away from the cutting zone and control the built-up-edge tendency that shows up when speeds creep too high.

Tool life planning should assume shorter intervals than Grade 5, and edge preparation should lean toward a slightly more robust hone to resist the higher cutting forces this alloy generates, rather than the sharper, more fragile edges that work well on lower-strength titanium grades.