Product Overview

Our cold drawn seamless steel pipes are high-precision tubular products manufactured by drawing hot-rolled seamless tube billets through precision dies at room temperature. Combining the inherent structural reliability of seamless pipes with the exceptional dimensional accuracy of cold working technology, these pipes feature excellent surface finish, uniform wall thickness and extremely tight tolerances. They are widely preferred in precision manufacturing, hydraulic systems and high-end industrial applications where hot-rolled pipes cannot meet accuracy requirements.

Manufacturing Process

1. Raw Material Preparation: Qualified hot-rolled seamless tubes are selected as base billets, with pre-inspection on surface defects and dimensional conformity.

2. Pickling & Lubrication: Billets undergo acid pickling to remove surface oxide scale, followed by phosphating and saponification to form a uniform lubricating film for smooth drawing.

3. Cold Drawing: The tube is pulled through precision tungsten carbide dies at ambient temperature to reduce outer diameter and wall thickness. Multi-pass drawing is applied for specifications with high reduction ratio.

4. Heat Treatment: Stress relief annealing or full annealing is performed to eliminate internal stress generated by cold working, and to adjust mechanical properties (strength, ductility, toughness) as required.

5. Straightening & Cutting: Tubes are precisely straightened to guarantee straightness accuracy, then cut to specified lengths with flat and burr-free end faces.

6. Finishing & Inspection: Final surface finishing, dimensional verification, non-destructive testing (NDT) and performance testing are conducted before packaging and delivery.

Key Features

· Ultra-high dimensional accuracy: Strictly controlled OD, ID and wall thickness tolerances far tighter than hot-rolled pipes, ensuring high interchangeability for precision assembly.

· Premium surface quality: Smooth, scale-free inner and outer surfaces with low roughness, greatly reducing or eliminating subsequent machining processes and cutting downstream production costs.

· Excellent wall uniformity & concentricity: Uniform wall thickness distribution and high coaxiality, ideal for high-precision machining and dynamic load applications.

· Adjustable mechanical properties: Cold working strengthening improves tensile strength and surface hardness; optional annealing treatment provides excellent ductility and toughness to match different performance demands.

· Broad small-size coverage: Capable of producing small-diameter, thin-wall seamless tubes that cannot be manufactured via hot rolling processes.

· Flexible customization: Support custom dimensions, length tolerances, surface treatments and end processing (threading, chamfering, grooving, etc.) to match specific project needs.

Main Applications

· Precision machinery industry: Hydraulic and pneumatic cylinder barrels, bearing sleeves, precision mechanical structural parts, textile and printing machinery components.

· Automotive manufacturing: Drive shafts, fuel injection pipes, shock absorber tubes, exhaust system pipes and automobile chassis parts.

· Boiler & heat transfer equipment: Heat exchanger tubes, condenser tubes, economizer tubes and small-diameter high-precision boiler tubes.

· Hydraulic & pneumatic systems: High-pressure hydraulic piping, pneumatic element tubes and instrumentation connecting pipes.

· Petrochemical & chemical industry: Small-diameter process piping, instrument tubing and corrosion-resistant fluid delivery lines.

· Instrumentation & medical equipment: Precision instrument housings, sensor components and medical device tubing.

· Structural engineering: High-precision structural supports, automation equipment frames and mechanical fabrication parts.

Standards & Specifications

Applicable Standards

· ASTM / ASME: A106 Gr.A/B/C, A53 Gr.B, A179, A192, A333 Gr.1/6

· DIN: DIN 2391 St37.4 / St44.4 / St52.4; DIN 1629; DIN 17175

· EN: EN 10305-1, EN 10297-1

· GB: GB/T 3639, GB/T 8162, GB/T 8163, GB/T 3087

Dimension Range

· Outer Diameter: 6 mm – 219 mm (custom sizes available upon request)

· Wall Thickness: 1 mm – 20 mm

· Length: 3m / 6m / 12m fixed length, or custom cut-to-length with strict tolerance

Common Steel Grades

· Carbon steel: 10#, 20#, 45#, Q235B, Q355B, A106 Gr.B, A53 Gr.B, St37.4, St52.4

· Low alloy steel: 16Mn, Q345B/C/D, 15CrMo

· Alloy steel: 12Cr1MoV, 40Cr, Cr5Mo, 20CrMo

Quality Assurance

All cold drawn seamless steel pipes are manufactured under an ISO 9001 certified quality management system, with full material traceability from raw billet to finished product. Each batch undergoes rigorous inspection procedures including dimensional measurement, surface quality check, hydrostatic pressure testing, eddy current testing (ET), ultrasonic testing (UT) and mechanical property verification.

Third-party inspection by SGS, BV, TÜV and other authoritative institutions is available upon customer request. We provide professional technical support and reliable global delivery services for distributors, machinery manufacturers, engineering contractors and end users worldwide. For detailed quotations and full product catalogs, please contact our sales team directly.