PENETRANT TESTING MATERIALS
Penetrant Testing Materials The penetrant materials used today are much more sophisticated than the kerosene and whiting first used by railroad inspectors near the turn of the 20th century. Today's penetrants are carefully formulated to produce the level of sensitivity desired by the inspector. To perform well, a penetrant must possess a number of important characteristics. A penetrant must: spread easily over the surface of the material being inspected to provide complete and even coverage. be drawn into surface breaking defects by capillary action. remain in the defect but remove easily from the surface of the part. remain fluid so it can be drawn back to the surface of the part through the drying and developing steps. be highly visible or fluoresce brightly to produce easy to see indications. not be harmful to the material being tested or the inspector. All penetrant materials do not perform the same and are not designed to perform the same. Penetran...