♦ The details of Non magnetic Drill collar as follows,
1. Material: P550,P540,P530
2. Shape: It is the round pipe with smooth surface and thick wall, and the both ends are machined screw thread for connection.
3. Use: It is mainly used for the inspection in the process of petroleum drilling.
4. Standard: API Spec 7-1 or SY/T5144 Standard.
5. Inspection&Test: When producing, traceability are maintained from the receipt of raw material to completion of final products, and serial numbers are die-stamped on each workpiece body. During each manufacturing process, inspection and test are performed.
6. Magnetic permeability(MPS=1×105/4∏A/m)
1). Average: Ur<1.010.
2). Magnetic Field Gradient: ΔB≤0.05μT.