4    Principle A cyclic tensile test with a constant load range is imposed on a cylindrical specimen under suitable test conditions within the stress range where SCG is achieved. A circumferential notch is machined in the center of the test specimen to enable crack initiation and SCG to the final failure of the specimen. The … Continue reading ISO 18489 – Determination of Resistance to Slow Crack Growth Under Cyclic Loading — Cracked Round Bar Test Method – Equipment