According to the American Petroleum Institute APISPEC5CT1988 first edition of the provisions of hydrostatic test, flattening test, sulfide stress corrosion cracking test, hardness test (ASTME18 or E10 latest version of the provisions), tensile test, transverse impact test (ASTMA370, ASTME23 And the latest version of the relevant standards), grain size determination (ASTME112 latest version or other methods).
(2) The inner and outer surfaces of the casing shall not be folded, hairy, delaminated, cracked, rolled and scarred. These defects should be completely removed, the depth of removal shall not exceed 12.5% of the nominal wall thickness
(3) the outer surface of the coupling shall not be folded, hairline, from the layer, crack, rolling fold, scar and other defects.
(4) Casing and coupling thread surfaces shall be smooth and do not allow burrs, torn and other defects that are sufficient to cause the threads to interrupt the strength and tight connection.