NAS 4006 Compliance
High Purity AlumiPlate® Aluminum for NAS 4006 Fastener Systems
99.99% pure electroplated aluminum is an ideal coating for fasteners and fastener systems to meet NAS 4006 coating requirements. AlumiPlate Inc. can certify full compliance to this exacting standard.
NAS 4006 is the National Aerospace Standard that governs the application of aluminum coatings for fasteners, including titanium fasteners. This specification is commonly used for high strength steel, titanium, Inconel and Hastelloy aerospace fasteners that require corrosion resistance to environmental corrosion or to eliminate galvanic corrosion with dissimilar metals. The required coating thickness is 0.0002” – 0.0005”. Processing at temperatures higher than 400 °F is not allowed. As long as performance requirements are met, any coating process can be used (strike layers are allowed).
NAS 4006 Aluminum Coating Specification Requirements
The National Aerospace Standard fastener specification lists aluminum coating performance criteria and test methods for thickness, coverage, appearance, adhesion, fluid resistance, paint stripper resistance, embrittlement, corrosion protection and heat protection on aerospace fasteners.
Thickness – 0.0002 to 0.0005 inches per MIL-STD-1312
Coverage and Appearance – visual examination for coverage and uniformity (pin holes, porosity, blisters, nodules and pits not allowed).
Adhesion – destructive adhesion test showing no separation under magnification (scrape or bend to rupture)
Fluid resistance – no blistering or loss of adhesion when exposed to phosphate ester hydraulic fluid (Aerosafe 2300 or equivalent) at 150 °F for 30 days.
Paint stripper resistance – no blistering or loss of adhesion when exposed to MIL-R-81294 paint stripper at room temperature (75 °F +/- 5 °F).
Embrittlement – no cracking after installing fasteners (using 80% of rated ultimate load) in 7075-T6 aluminum block. Metallurgical examination of polished and mounted samples after exposure for 72 hours at 300 °F +/- 10 °F.
Corrosion protective properties – same or better performance as cadmium plated control block in a modified accelerated exposure procedure (modified 14-day Acid-Salt Spray Test per ASTM B-287).
Heat Protection – destructive adhesion test showing no separation under magnification (scrape or bend to rupture) after heating at 375 °F +/- 25 °F for four (4) hours and air cooling.
Aluminum electroplating meets all specification requirements for National Aerospace Standard fasteners, with confirming documentation via an order certification.
Contact us for more information or to discuss your application in more detail.