Cold-Drawn/Cold-Rolled Seamless Steel Pipe

High precision cold drawn seamless steel tube refers to the precision steel pipe with high dimension precision (inside diameter and outside diameter), good surface finish, excellent roundness and straightness, and uniform wall thickness. It can be widely used in mechanical structure and hydraulic equipment. This cold rolled or cold drawn seamless steel tube can greatly reduce the machining time, improve the material utilization rate and improve the product quality.

• General length is between 2000 mm to 7000 mm.
• The fixed length and multiple length of cold drawn seamless steel tube should be controlled within the general length range. The allowable deviation of total length should be in accordance with the following rules:
• 1) For precision steel pipes with the length of equal to or less than 5000 mm, the deviation should be within 0 to +5 mm.
• 2) For cold drawn seamless steel tubes with the length of more than 5000 mm, the deviation should be between 0 to +10 mm.
• For the delivered precision steel pipes with multiple lengths, we should leave notch margin according to the following regulations:
• 1) For pipes with the outside diameter of equal to or less than 159 mm, the notch should be within 5 to 10 mm.
• 2) For cold drawn seamless steel tubes with the outside diameter of more than 159 mm, it should be between 10 to 15 mm.

• When this precision steel pipe is in cold finished (hard) state (BK state) or in cold finished (soft) state (BKW state), the curvature should not exceed 3.0 mm/m.
• When cold drawn seamless steel tube is in cold finished and stress-relieved state (BKS), annealed state (GBK) or normalized state (NBK), the tortuosity should not exceed 1.5 mm/m.

• Delivery weight of this precision steel pipe should meet the relevant specifications. The density of steel is 7.8 5kg/dm3.
• We can deliver cold drawn seamless steel tubes with theoretical weight according to the buyer's requirements. This should be negotiated between the two parties and be specified in the contract. The tolerance of actual delivery weight and theoretical weight should comply with the following requirements:
• 1) The tolerance of each precision steel pipe should be within -8% to +10%.
• 2) The tolerance of cold drawn seamless steel tubes with the batch weight of 10 tons is at least ±7.5%

• Steel inner and outer surfaces should be smooth. Localized pit, scratch and small scratch shall not exceed the depth of 0.08 mm. The actual thickness of precision steel pipes with those flaws should not be smaller than the allowable minimum deviation of wall thickness.
• Other defects on the inner and outer surfaces of cold drawn seamless steel tubes can be removed by appropriate methods. After removal, the actual wall thickness should not be less than the allowed minimum thickness deviation.
• For the inside and outside surfaces of precision steel pipes delivered in cold-finished state, phosphate and lubricant adhesion layer are allowed to exist.
• For the inside and outside surfaces of cold drawn seamless steel tubes delivered in heat treatment state, oxide film is allowed to exist because it does not influence the surface inspection, but loose oxide scale or oxide skin is forbidden.

Mechanical Properties

Founded in 1984, Jiangyin Changjiang Steel Tube Making Factory is a professional manufacturer of precision steel pipes in China. Our products mainly cover casing, tubing, line pipe, drill pipe, high pressure boiler pipe, marine pipe, cylinder tube, hydraulic prop tube, fluid pipe, structure pipe, etc. They have passed API 5CT, API 5L, API 5DP, CCS, LR, DNV, ABS, NK, BV, GL, PED, SGS, ISO9001:2000 and ISO14001:2004 certifications. Our cold drawn seamless steel tubes have won widespread praise and recognition by customers.

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