International Organization for Standardization

Fasteners - Preloading Test for the Detection of Hydrogen Embrittlement - Parallel Bearing Surface Method - First Edition
 N 15330

Annotation

This International Standard specifies a preloading test which is able to detect the occurence of hydrogen embrittlement of fasteners at room temperature.

This test is applicable to

— metric bolts, screws and studs;

— thread rolling screws;

— self-tapping screws;

— self-drilling screws;

— nuts;

— washers

which are made of steel and are under tensile stress.

The test shall be carried out within a temperature range of 10 °C to 35 °C.

The test is suitable only for in-process control and may be carried out after any step of the manufacturing process. It is not intended as an acceptance test. It is capable of assessing differences or changes in processing conditions or techniques and to determine the effectiveness of the various processing steps including pre- and post-coating treatments (baking) to reduce the mobile hydrogen in the fasteners.

This test does not relieve the manufacturer or processor from the responsibility of imposing and monitoring suitable process control.

NOTE The chance of detecting hydrogen embrittlement decreases significantly if the test is started more than 24 h after the last step of manufacturing process. Therefore, in normal cases this test is not suitable for acceptance testing.