1.1 This test method describes mechanical test methods and defines acceptance criteria for coating and plating processes that can cause hydrogen embrittlement in steels. Subsequent exposure to chemicals encountered in service environments, such as fluids, cleaning treatments or maintenance chemicals that come in contact with the plated/coated or bare surface of the steel, can also be evaluated. 1.2 This test method is not intended to measure the relative susceptibility of different steels. The relative susceptibility of different materials to hydrogen embrittlement may be determined in accordance with Test Method F1459 and Test Method F1624 . 1.3 This test method specifies the use of air melted AISI E4340 steel per SAE AMS-S-5000 (formerly MIL-S-5000) heat treated to 260 to 280 ksi (pounds per square inch 1000) as the baseline. This combination of alloy and heat treat level has been used for many years and a large database has been accumulated in the aerospace industry on its specific response to exposure to a wide variety of maintenance chemicals, or electroplated coatings, or both. Components with ultimate strengths higher than 260 to 280 ksi may not be represented by the baseline. In such cases, the cognizant engineering authority shall determine the need for manufacturing specimens from the specific material and heat treat condition of the component. Deviations from the baseline shall be reported as required by 12.1.2 . The sensitivity to hydrogen embrittlement shall be demonstrated for each lot of specimens as specified in 9.5 . 1.4 Test procedures and acceptance requirements are specified for seven specimens of different sizes, geometries, and loading configurations. 1.5 Pass/Fail Requirements For plating/coating processes, specimens must meet or exceed 200 h using a sustained load test (SLT) at the levels shown in Table 3 . TABLE 1 Lot Acceptance Criteria for Notched Specimens Type Item Sampling of Each Lot Requirement/Method 1 Tensile Strength 4 each Test Method E8. Tensile strength of each specimen must be within 10 ksi of the average. 1 Hardness A 5% 51 to 53 HRC per Test Methods E18 . Round the average of three readings per specimen per Practice E29 . 1 Dimensions 100% Meet tolerances of corresponding drawings. Notch dimension verified with shadow graphic projection at 50 to 100 or equivalent. 1 Notched Fracture Strength (NFS) 10 ea Test Methods E8/E8M . NFS of each specimen must be within 10 ksi of the average. 1c Self-loading notched round specimen bend fixture, Fig. A2.7 10 ea Alternate: The number of turns of the loading bolt, which is required to produce fracture in each specimen, must be within 5% of the average. 1d Self-loading notched C-Ring bend fixture, Fig. A2.8 10 ea Alternate: The change in diameter at fracture load for each specimen must be within 0.008 inches of the average. A If the hardness requirements of any of the sampled specimens are not satisfied, only those specimens of the lot that are individually inspected for conformance to these requirements shall be used for testing. TABLE 2 Electroplating Bath Compositions and Operating Conditions for Sensitivity Test Item Treatment A Treatment B Bath composition: Range Optimum Cadmium (as CdO) 2.9 to 5.5 oz/gal (22 to 41 g/L) 4.5 oz/gal (33.7 g/L) same as Treatment A Total Sodium cyanide (NaCN) 12.0 to 16.0 oz/gal (89.9 to 120 g/L) 14 oz/gal (104 g/L) same as Treatment A Ratio NaCN to CdO 2.8/1 to 6.0/1 3.0/1 same as Treatment A pH 12.0 or greater 12.0 same as Treatment A Temperature 7090F (2132C) 75F (24C) same as Treatment A Sodium hydroxide (NaOH) A 1.0 to 3.2 oz/gal (7.5 to 24.0 g/L) 2.5 oz/gal (18.7 g/L) same as Treatment A Brightener such as Colcad 100 B or equivalent Manufacturer's suggested range None Electroplating current 10 A/ft2 (108 A/m2) 60 A/ft2 (645 A/m 2) Electroplating time 30 minutes 6 minutes Baking Baking temperature 375 25F (190 14C) same as Treatment A Baking time: Type 1 Specimen Do Not Bake ...