INTERN MPAPS G-4523 PDF

This specification covers the general coating requirements, part performance, fastener torque-tension requirements, quality, KCC, source approval and quality control, packing, shipping, and identification requirements, designation on drawings, and approved products.

Restricted Chemical Substances

Effective January 1, 2007, all product supplied to the requirements of this specification must comply with the requirements of the MPAPS B-50 specification.

APPLICATION

This specification covers the requirements for a silvery, corrosion resistant, non-electrolytically applied, water-based coating for steel substrates. The coating is heat-converted from an aqueous dispersion of zinc and aluminum flakes, and contains a PTFE lubricant dispersed through the film thickness. This coating system is free of both hexavalent and trivalent chromium, and is suitable for high hardness parts since hydrogen embrittlement is not induced by the process. Typical applications include interior and exterior parts requiring lubrication and good corrosion resistance, externally and internally threaded fasteners M5 and larger, internally recessed fasteners, stampings, brackets, clips, clamps, etc. (For internal recessed fasteners, such as socket head or Torx head screws, it is recommended that the coating be applied via dipspin tilt-tumble equipment.)

This coating should not be used on parts which will come in contact with uncoated copper, magnesium, or stainless steel, but will provide good bi-metallic corrosion resistance when in contact with aluminum. Coating should not be used on materials which might be adversely affected by a cure temperature range of 288-315°C (550-600°F). The maximum continuous service temperature is 280°C (536°F).