35NCD14 is a French AFNOR-designated nickel-chromium-molybdenum low-alloy steel. Under AFNOR's designation convention, "35" indicates roughly 0.35% carbon, and "NCD" identifies nickel, chromium, and molybdenum as the alloying elements in decreasing order of content, with the trailing coefficient applying to nickel — placing it in the neighborhood of 3.5%. That carbon level is too high for efficient case-hardening (carburizing steels are almost always kept below roughly 0.25% carbon so the core stays soft), so despite the superficial resemblance to lower-carbon Ni-Cr-Mo case-hardening grades, 35NCD14 is better understood as a high-strength, through-hardening engineering steel: supplied and machined annealed or normalized, then quenched and tempered to reach final mechanical properties.

It belongs to the same general Ni-Cr-Mo family as the better-documented 35NCD16 (DIN 36NiCrMo16 / Wnr. 1.6773) and SAE 4340, sharing the combination that makes this class of steel prized for heavily stressed structural and mechanical parts: nickel for core toughness and fatigue resistance, chromium and molybdenum for deep hardenability and elevated-temperature strength. In practice, grades in this family are used for critical, highly loaded components — aerospace and engine parts, high-strength fasteners, tooling, and parts subject to severe fatigue — where the combination of tensile strength and fracture toughness justifies the added alloy cost over a simpler Cr-Mo steel.

No independently verifiable Wnr./DIN cross-reference was located specifically for the "35NCD14" AFNOR variant. The closely related 35NCD16 (DIN 36NiCrMo16, Wnr. 1.6773) is a higher-nickel cousin in the same Ni-Cr-Mo family, not a formal equivalent — confirm designation and composition against AFNOR documentation or mill certification for critical applications.

Like other alloy steels in the Ni-Cr-Mo family, 35NCD14 is noticeably tougher to machine than a plain carbon or straight Cr-Mo steel of similar carbon content. The nickel content raises toughness and ductility, so the material resists clean shear at the cutting edge and cutting forces run higher for a given depth of cut, while chromium and molybdenum carbides add abrasive wear at the flank. Heat generation at the tool-chip interface is a bigger factor here than on lower-alloy grades, favoring coated carbide grades with strong hot hardness and thermal stability over general-purpose grades.

Chip control needs more attention than on a free-machining or plain carbon steel — in the softer annealed/normalized condition this grade is typically machined in, it can produce long, stringy chips without a well-matched chipbreaker geometry, so chipbreaker selection matters more here than on easier-cutting materials.

Rigid machine setups, adequate coolant delivery to manage heat, and a carbide grade selected specifically for tough alloy steels rather than mild steel are the biggest levers for controlling tool wear and holding tolerance. As with other Ni-Cr-Mo grades destined for later heat treatment, dimensional allowance for quench-and-temper distortion is worth planning for alongside tool selection.