1.1 This test method covers a Ball Rust Test (BRT) procedure for evaluating the anti-rust ability of fluid lubricants. The procedure is particularly suitable for the evaluation of automotive engine oils under low-temperature, acidic service conditions. 1.2 Information Letters are published occasionally by the ASTM Test Monitoring Center (TMC) to update this test method. Copies of these letters can be obtained by writing the center. 1.3 The va