Aug 23, 2018 After the pipe have been cast and run through the heat treatment process of annealing, the following tests and inspections are performed. Charpy test confirms the impact resistance of the pipe wall. Tensile test confirms flexibility (elongation) and strength properties of the ductile iron ( 60- 42- 10 ) grade. 60,000 psi tensile strength / 42,000 yield strength / 10% elongation ... All of the products MonotaRO offers are subject to Japanese local laws, regulations, and certification standards. Please make sure that it may or may not meet requirements of your country and/or international organizations, including but not limited to, UL Certification, China Compulsory Certificate system, and Halal.