SAE/AISI 3415, equivalent to DIN/EN 14NiCr10 (Wnr. 1.5732), is a genuine low-carbon nickel-chromium case-hardening (carburizing) steel. Unlike higher-carbon Ni-Cr grades in the same family that are through-hardened, 3415's carbon content is capped at roughly 0.10–0.17% — deliberately kept low so the core stays soft, ductile, and able to absorb shock loading, while a carburized case builds a hard, wear-resistant surface layer on top. Nickel in the 2.25–2.75% range gives this grade its core toughness, and chromium contributes hardenability so the case-hardening process produces a consistent, deep-enough case for demanding components.

This profile makes 3415 a natural choice for gears, cams, rollers, and similar power-transmission components that need a hard, fatigue-resistant wearing surface paired with a tough core that won't crack under cyclic or shock loading. It sits below the more heavily alloyed aerospace-grade carburizing steels (like 9310) in total alloy content, making it a somewhat lighter-duty but still capable option in the same general application space.

3415's low carbon content makes it relatively cooperative to machine in the annealed or normalized condition it's typically supplied in — the nickel-chromium alloy content raises cutting forces above a plain low-carbon steel, but noticeably less than a higher-carbon through-hardening grade would. Nickel does add a bit of gumminess and a tendency toward built-up edge at low speeds or with a dull edge, so staying within the recommended speed range and keeping the cutting edge sharp both help keep chip formation and surface finish consistent.

Chip control in the annealed state is generally good, producing manageable chips with standard chipbreaker geometry. Once a part is carburized and case-hardened, further machining is essentially limited to grinding or hard finishing on the hardened surfaces — all conventional turning, milling, and drilling should be completed beforehand.

Because gear blanks and similar precision components made from this grade often carry tight dimensional and surface-finish requirements ahead of carburizing, a rigid setup and sharp, well-supported edge matter as much for part accuracy as for tool life. Coated carbide with good toughness handles the alloy content well without sacrificing the finish these parts typically demand.