Aerospace cadmium plating
Low-hydrogen-embrittlement cadmium and hydrogen relief in a calibrated oven, with the traceability the sector demands.
Hydrogen embrittlement in a structural component gets no second chance.
Aerospace is the sector where the coating standard and the heat-treatment standard travel together. Low-embrittlement cadmium is specified to AMS-QQ-P-416 — an aeronautical-sector standard, not an oil and gas one, where the designation would be ASTM B766 class 12 type II. Swapping one for the other on a drawing is a specification error.
The reason cadmium resists substitution here is galvanic compatibility with aluminum. On a light-alloy structure, an electrochemically poorly chosen coating does not eliminate corrosion: it transfers it to the part it was meant to protect.
What the audit checks is not the oven’s nominal temperature: it is the uniformity survey that proves the whole load reached the range, and the traceable thermocouple calibration. A part that sat in a cold spot of the oven did not get full relief, and it is the one that fails in service.
What we apply in this sector.
Cadmium
Electrolytic cadmium plating to ASTM B766 class 12 type II, with 1,000 hours of salt spray in an ASTM B117 report from an ISO/IEC 17025 accredited test.
Hydrogen embrittlement relief
Hydrogen-relief heat treatment between 150 °C and 250 °C, immediately after galvanic coating, in ovens calibrated to API 6A.
NanoGalv®
Nanostructured zinc-nickel to ASTM B1025-25, which passes 10,000 hours of salt spray to red rust at 10 µm in Modumetal’s ASTM B117 test.
What specifiers usually ask.
Which cadmium standard applies in aerospace?
AMS-QQ-P-416, the aeronautical-sector standard. ASTM B766 class 12 type II is the oil and gas designation. Both cover electrodeposited cadmium, but they are not interchangeable on a drawing.
What is LHE cadmium?
Low Hydrogen Embrittlement — the process variant formulated to generate less hydrogen during deposition, used on high-strength steel in aircraft parts. It reduces hydrogen uptake, and it does not replace the thermal relief that follows.