SAE/AISI 9262 is a silicon-chromium spring steel, closely related to the 9255 silicon-manganese grade but with a chromium addition that further improves hardenability and gives a slightly more consistent through-hardened structure in thicker spring sections. Like other members of the silicon spring steel family, the silicon content is what really sets this grade apart — it raises the elastic limit well above what a plain carbon steel of similar hardness can achieve, letting a part flex repeatedly without taking a permanent set.

The combination of high carbon, silicon, and chromium gives 9262 excellent fatigue strength and resistance to sagging under sustained load, which is exactly why it shows up in demanding leaf spring, coil spring, and torsion bar applications, particularly where higher stress levels or larger cross-sections call for the extra hardenability chromium provides over a straight Si-Mn grade. It's almost always machined in a hardened, spring-tempered condition rather than soft annealed stock.

9262 tends to reach the machine shop already hardened to spring temper, since soft annealed stock in this grade is uncommon outside of forming operations. At spring hardness, the combined silicon and chromium content pushes cutting forces and edge temperatures noticeably above what a plain or low-alloy carbon steel of similar hardness would produce, and flank wear driven by the fine, hard carbide structure is the main constraint on tool life.

Chip formation is generally short and segmented at this hardness level, which helps chip evacuation but also subjects the cutting edge to repeated thermal and mechanical shock rather than a smooth continuous cut — a coated grade with good edge toughness handles that better than a hard but brittle uncoated substrate. Because the alloy content is a little higher than on straight Si-Mn spring steels, expect slightly more aggressive tool wear than on 9255 at comparable hardness.

Rigid setups, short tool overhang, and steady feed rates that keep the edge engaged rather than rubbing all matter more on this grade than on softer steels — any hesitation or light cutting risks work-hardening the surface and making the next pass harder to start cleanly.