AISI 4130 4140 4145 Hollow Bar Seamless Steel Tube

ASTM A4130 4140 AISI 4130 4140 4145 Hollow Bar Seamless Steel Tube



Outer diameter: 83-254 mm, Wall thickness: 7 to 60 mm, length: not more than 12 meters.

Tolerance for OD and ID

Cold drawn: within ±0.2mm

Cold rolled: within ±0.1mm

Tolerance for Wall Thickness

Hot rolled: within +/-5%,

Cold drawn: within 0.6mm


Hot Rolled, Cold Drawn, Precision Rolled

Delivery Condition

Hot rolled, Cold drawn, Annealed, Normalized, Quenched and tempered.

Surface Condition

Black surface, Rough turned, Peeled.


Oil exploration, automobiles, machinery, etc.


More grades we can supply.



We mainly specialized in manufacturing and marketing on steel tubes & pipes. Now we have five manufacturers with total capacity of 60,000 tonnes of Cold Drawn/Rolled Seamless, 50,000 tonnes of Electrical Resistance Welded, 30,000 tonnes of Cold Drawn Welded(DOM) and 30,000 tonnes of Cold Drawn Special Shape/Large Diameter, the first phase(10,OOO tonnes) of 30,000 tonnes high alloy project already completed. Total annual capacity of 200,000 tonnes for above five types and manufacturing base of high quality steel tubes & pipes(medium & small diameter) will be realized soon. Our tubes & pipes can be widely used in Power Plant Boiler, Heat Exchanger, Automobile Components, Mechanical Structure, Bearing Machining, Shipbuilding, Bridge Construction, Petroleum Exploration & Transportation, and some other relative fields.


Continuous improvement

The development of more than ten years, we have a set of complete, standardized quality control management system and quality program. The establishment of quality system internal audit team, through the strengthening of the usual supervision and inspection to continue to standardize the management of the company, meet the company's continuous improvement. The company has established the quality control procedures of the main production process, from the quality system and quality control to ensure the long-term stable development.


Quality assurance department detection center equipped with direct reading spectrometer (Germany), impact test machine, universal material testing machine, optical microscope, hardness tester, infrared spectroscopy steel analyzer and other modern testing equipment. The ultrasonic flaw detector has 4 eddy current flaw detector and four channels, six channels at the same time each 1.


German LOI atmosphere international first-class is tempering furnace and protective atmosphere bright normalizing furnace on heat treatment temperature precise automatic control ability, to provide a strong guarantee, laid the foundation for the build quality steel production base for the intrinsic quality .