Seamless Cold Drawn Steel Pipe

Seamless Cold Drawn Steel Pipe

A seamless cold drawn steel pipe is a type of high-precision seamless steel tube manufactured through the cold drawing process. This process involves pulling (drawing) a seamless steel shell (hot-rolled or extruded) through a die and over a mandrel at room temperature to reduce its diameter and wall thickness to precise dimensions.

This method produces pipes with superior surface finish, tighter dimensional tolerances, enhanced mechanical properties, and a more uniform microstructure compared to hot-finished pipes. They are widely used in applications requiring high precision, strength, and reliability.

Key Characteristics & Advantages:

• Excellent Surface Finish: Smooth, clean surface with minimal scale or imperfections.

• High Dimensional Accuracy: Very tight tolerances on Outside Diameter (OD) and Wall Thickness (WT).

• Enhanced Mechanical Properties: The cold working process significantly increases yield and tensile strength.

• Improved Machinability: The uniform and often annealed structure makes them ideal for subsequent machining operations.

• Wide Range of Applications: Used in precision machinery, hydraulic and pneumatic cylinders, automotive components, bearing sleeves, and critical structural parts

1. Common Materials / Grades

Seamless cold drawn pipes are typically made from carbon steel and alloy steel. The most common standard specifications include:

• ASTM A519: Standard Specification for Seamless Carbon and Alloy Steel Mechanical Tubing. This is the most prevalent standard for cold drawn mechanical tubing.

• ASTM A106: Standard Specification for Seamless Carbon Steel Pipe for High-Temperature Service (can be cold drawn for finishing).

• DIN 2391: German standard for Seamless Precision Steel Tubes - Part 1: Cold Drawn Tubes.

• JIS G3445: Japanese Industrial Standard for Carbon Steel Tubes for Machine Structural Purposes.

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• Common Grades:

• Carbon Steels: 1020, 1025, 1026, 1045, C45 (1.0503), ST52 (1.0570)

• Alloy Steels: 4140, 4130, 4340, 8620, 42CrMo4 (1.7225), 34CrMo4 (1.7220)

• Bearing Steel: 100Cr6 (1.3505, AISI 52100)

Important Note on Properties:

Tags: seamless steel pipe, cold drawn steel pipe 

• "As-Drawn" vs. "Heat Treated": The values above are typical for the "as-drawn" condition. Heat treatment can drastically alter these properties. For example, a quenched and tempered 4140 tube can achieve a yield strength exceeding 965 MPa (140 ksi).

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• Anisotropy: Cold drawing creates directional properties. Mechanical properties are generally higher in the longitudinal direction (along the length of the tube) compared to the transverse direction.

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• Specification Governs: The required mechanical properties are always defined by the purchasing specification (e.g., ASTM A519, DIN 2391-1) and the specific grade ordered.

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