Oil casing pipe thread common imperfections and defects
1, Black top oil casing thread
2, Broken thread
3, Burr
4, Tremor
5, Marks
6, Scored thread
7, Dimples, indentations
8, Sub-standard thread height
9, Flash
10, Tear
11, Camfered insufficiency, bevel failed
12, pitting thread
13, casing deformity buckle