Chromium Nitride (CrN)

CrN is a single-layer PVD chromium nitride coating that trades peak hardness for toughness. Where the harder titanium-based nitrides chase cutting performance, CrN exists for the jobs that punish a brittle film: it is ductile, anti-galling, corrosion- resistant, and unusually willing to be laid down thick. That combination makes it the default surface where a part has to resist sticking, seizing, and chemical attack rather than sheer abrasion.

What the numbers say

• Hardness ~1,800–2,500 HV (typical ≈2,000). Softer than the TiN/TiAlN family by design — the missing hardness buys ductility and crack resistance. Spread is genuine and method-dependent. [eifeler, minitools, brycoat]
• Max service ~700°C, oxidation-limited (typical 700°C, with one conservative source at 600°C). The figure is oxidation onset in air, not a melting limit — CrN holds heat noticeably better than TiN. [eifeler, brycoat, oerlikon-balinit-d, minitools, calico]
• Coefficient of friction ~0.3–0.5 against steel (typical ≈0.4). Counterface matters: eifeler and MiniTools measure against 100Cr6, Oerlikon runs dry vs steel per ASTM G99 ball-on-disc, BryCoat against unspecified steel. The low-adhesion behaviour against non-ferrous metals is the real selling point. [eifeler, minitools, brycoat, oerlikon-balinit-d]
• Thickness 1–7 µm (typical ≈3 µm) — CrN is notable for thick-film capability, with vendors reporting up to 15 µm — deposited 200–450°C (typical ≈400°C), with low-temperature variants down to ~220°C for temper-sensitive substrates like CuBe. [eifeler, minitools, calico, brycoat]

Where it fits

CrN earns its place wherever galling, corrosion, and chemical attack outweigh raw abrasion: plastic and rubber injection moulds running aggressive fluorine/chlorine release agents, sheet-metal forming and stamping dies on low-strength or non-ferrous stock, and aluminium die-casting and machining where its low adhesion to non-ferrous metals keeps work from welding to the tool. Its thick-film capability and low deposition temperature also make it a common hard-chrome plating replacement on substrates that cannot tolerate hot processing.

Vendor-neutral note: these are general process properties for understanding tradeoffs — not a specification for your application. Real selection needs a coating house with your substrate, geometry, and duty data.