1.1 ,This test method employs a side-grooved, crack-line-wedge-loaded specimen to obtain a rapid run-arrest segment of flat-tensile separation with a nearly straight crack front. This test method provides a static analysis determination of the stress intensity factor at a short time after crack arrest. The estimate is denoted K_a. When certain size requirements are met, the test result provides an estimate, termed K_Ia, of the plane-strain crack-arrest toughness of the material.