Seamless Pipe (and tubing) is made by extruding a steel block or by drilling a solid steel bar. Next, the extrusion or the drilled steel bar is cold drawn through a dye to achieve the diameter and thickness needed. Because this process can cause mechanical hardening, sometimes the material is annealed and straightened as a final process. 

Seamless Pipe & Tubing is subdivided as:

Cold Drawn Seamless, or CDS, exhibits precise tolerances and a good surface finish.

Hot Finished Seamless, or HFS, has less critical tolerances and somewhat scaly finish and is not as strong as CDS.

For Drawn over Mandrel, or DOM tubing, the first stages of manufacturing are identical to ones used to make electric resistance welded tubing, but in the finishing stages the entire flash weld is taken out and the tube is cold drawn over a mandrel. A mandrel is a round object against which material can be forged or shaped. The cold drawn process provides the tube with better dimensional tolerances, improved surface finish and the strongest weld strength achievable.

1. Production technology: Hot-rolled and cold drawn

2. Executive standards: API5L , ASME B36.10, ASTM A106/A53

3.Specification range:

OD: OD: 1/8 – 30 inch (10.3-762mm), WT: 0.049”- 2.5” (1.24- 63.5mm)

WT: SCH10-SCHXXS

4. Materials: GrB, Q345B, X42-70, ST44, ST52 etc.

5. Testing: Eddy current/ Hydrostatic/Ultrasonic/ Intergranular Corrosion etc.

6. Packing: Bundles, seaworthy packing, or as required by customers.

7. Application:

API seamless pipe are widely used for petroleum, power generation, natural gas, coal gas, water and some solid materials, also ship-building, chemical fertilizer equipment etc.

Chemical Analysis