1. Steel grade of petroleum casing: H40, J55, K55, N80, L80, C90, T95, P110, q125, V150, etc.

2. Casing end processing form: short round thread, long round thread, partial trapezoid thread, special thread, etc.

3.  It is mainly used to support the well wall in the process of drilling and after completion to ensure the normal operation of the whole well.