Square 304 Stainless Steel Welded Pipe Laser Cutting Processing

304 stainless steel welded pipe is manufactured by roll-forming stainless steel coil or plate into a tubular shape followed by longitudinal welding. As an austenitic stainless steel grade, it offers excellent corrosion resistance, high dimensional accuracy, and a bright surface finish. The production process is efficient, cost-effective, and available in a wide range of sizes and specifications. Products are available as longitudinally welded pipe or spiral welded pipe.

304 stainless steel is the most widely used stainless and heat-resistant steel. It provides better corrosion resistance than 200-series stainless steel and performs well at high temperatures, withstanding up to 1000–1200°C. In recent years, with the rapid development of continuous rolling of high-quality stainless steel strip and advances in welding and inspection technology, weld quality has continuously improved. As a result, 304 stainless steel welded pipe has replaced seamless pipe in many applications — particularly heat exchanger tubes, decorative tubes, and low-to-medium pressure fluid pipes.

Key Features at a Glance:

• High corrosion resistance – 18–20% chromium content forms a dense chromium oxide passive film, resisting various acids and alkalis
• Good workability – High ductility, easy to form by hot or cold working, custom lengths available
• Bright surface – Smooth inner and outer surface finish, attractive appearance
• Cost-effective – Higher production efficiency, lower cost than seamless pipe, excellent value
• Hygienic & safe – Non-toxic, odorless, smooth surface inhibits bacterial growth

Product Details

Applicable Standards

304 stainless steel welded pipe is manufactured and supplied according to the following standards:

Manufacturing Process

Raw Material – Stainless steel coil or plate conforming to ASTM A240, grade 304/304L austenitic stainless steel

Forming & Welding – The steel strip is continuously roll-formed into a tubular shape, and the longitudinal seam is welded using automated methods. Common welding processes include TIG (GTAW), plasma arc welding (PAW), high-frequency welding (HFW), and laser welding. Welding is performed under protective atmosphere to prevent oxidation of the weld metal.

Post-Weld Treatment – Solution annealing (1050–1150°C) to relieve internal stresses, homogenize the metallurgical structure, and achieve mechanical properties close to seamless pipe. Inner and outer weld beads are removed to create a smooth inner surface and reduce flow resistance. Surface finishing options include pickling and polishing (#4, #6, #8 mirror finish) as required.

Inspection & Testing – Chemical composition analysis, mechanical property testing, hydrostatic testing or non-destructive testing (eddy current / ultrasonic), dimensional inspection.

Product Classification

Specification Table

General Specifications

Common Dimensions Table (Round Pipe)

Common dimensions for 304 stainless steel welded pipe are as follows:

Note: The above are common dimensions. Custom sizes are available upon request. Maximum OD up to 3000mm, maximum wall thickness up to 30mm.

Square / Rectangular Tube Dimensions

Square and rectangular tubes are manufactured to ASTM A554.

Applications

304 stainless steel welded pipe is widely used across the following industries due to its excellent combination of properties and cost-effectiveness:

Selection Guide

304 vs 304L – How to Choose?

Recommendation: If your piping system requires significant welding or will be exposed to conditions that risk intergranular corrosion, 304L is the preferred choice.