- Short Drill Collar
- 2016-11-05 11:14
- It's made from rolled or forged AISI4145H chrome-molybdenum steel. The content of chemical composition and microelement
- Integral Heavy Weight Drill Pipe
- 2016-10-26 12:52
- Made from AISI 4145H alloy steel and fully heat treated, all its physical properties conform to the latest API Spec. Hea