ASTM F1941 Specification

• Cleaning of Basis Metal—Thorough cleaning of the basis metal is essential in order to ensure satisfactory adhesion, appearance and corrosion resistance of the coating.
  Hydrogen Embrittlement Risk Management:
  
• Process Considerations — The following are some general recommendations for managing the risk of hydrogen embrittlement. For more detailed information refer to IFI-142. Clean the fasteners in non-cathodic alkaline solutions and in inhibited acid solutions.
  Use abrasive cleaners for fasteners having a hardness of 40 HRC or above and case hardened fasteners.
  Manage anode/cathode surface area and efficiency, resulting in proper control of applied current densities. High current densities increase hydrogen charging.
  Use high efficiency plating processes such as zinc chloride or acid cadmium. Control the plating bath temperature to minimize the use of brighteners.
  Select raw materials with a low susceptibility to hydrogen embrittlement by controlling steel chemistry, microstructure, and mechanical properties.
  
• Process Control Verification — Test Method F1940 should be used as a test method for process control to minimize the risk of hydrogen embrittlement. Periodic inspections should be conducted according to a specified test plan. The test plan should be designed based upon the specific characteristics of a process, and upon agreement between the purchaser and the manufacturer. The testing frequency should initially establish and subsequently verify over time, the ability of a process to produce parts that do not have the potential for hydrogen embrittlement.