ASTM E647 covers the standard test method for measurement of fatigue crack growth rates. Test specimens used in this test are notched and pre-cracked in fatigue. The test will cyclically load the test specimen and measure growth of the fatigue crack as a function of fatigue cycles. The crack growth rates are a function of the stress-intensity factor range. Depending on the specimen that will be tested, a unique grip and fixture will be used. Alignment of the grips is also necessary to insure that cracking measurements are valid indicators of fatigue crack resistance. TestResources specializes in Test Equipment, Machines & Fixtures that are used in material testing. We have the material testing machines that are used for ASTM E647 test standard. Call our applications engineers to talk with an expert in material testing. We will work with you to guarantee a test machine that fits your application.