API St 7CW pdf download Casing Wear Tests 4.4.3 Substantive changes to the material chemistry or application process shall require requalification of thematerial. 4.4.4The test specimen length and diameter dimensions shall be defined by this standard.4.5Test Agency Requirements 4.5.1 The test agency shall conduct tests in accordance with this standard. 4.5.2The test agency shall be responsible for assuring itself, the...