Stainless Steel Welded Pipe

Specifications

Item	Stainless Steel Welded Pipe
Raw Material	Stainless Steel Strip
Material Grade	201 / 202 / 304 / 304L / 316 / 316L / 321 / 310S
Cross Section	Round, Square, Rectangular, Oval, Customized Special Profiles
Surface Finish	2B / BA / HL / Mirror Polished / Color PVD Coating
Outer Diameter / Side Width	Round pipe: 6mm – 3000mm; Square & Rectangular pipe: 10×10mm – 800×800mm
Wall Thickness (WT)	0.5mm – 70.0mm, SCH10, SCH40, SCH80, XXS
Standard Length	Max 12 meters
MOQ	10 Tons
Production Lead Time	8 – 15 days
Execution Standards	ASTM A312, ASTM A249, ASTM A269, ASTM A270, EN 10217, JIS G3463, GB/T 12771

Surface Finishes

• 2B: A silvery-white matte finish, representing the original, most basic state; a common surface finish for industrial-grade tubing.
• BA: A soft mirror finish, short for “bright annealed,” featuring a naturally bright, smooth, and clean surface.
• HL: Straight-grain brushed finish, featuring fine, elongated straight lines on the surface; fingerprint- and scratch-resistant; one of the most commonly used surface finishes.
• Mirror Finish: 4K/8K multi-stage precision polishing, resulting in a high-definition reflective surface; 8K is the industry-standard mirror finish, used for decorative and artistic applications.
• Colored PVD: Colored via physical vapor deposition (PVD); we produce a wide range of color options, including titanium gold, black titanium, rose gold, blue, green, and orange.

Notes on Pickling Processes

We offer two processes: “Weld Seam Pickling” and “Full Immersion Pickling.” For industrial fluid pipes, we strongly recommend full immersion pickling to ensure uniform corrosion resistance throughout the entire pipe.

Cross-Section Types and Uses

All tubes are manufactured using a cold-forming and welding process with stainless steel strips. We offer both standard and custom-shaped tubes:

1. Round Tubes: These distribute stress evenly and have the widest range of applications, making them suitable for fluid conveyance, sanitary piping, and chemical process piping. We can produce the full range of SCH standards with thickened walls.
2. Square and Rectangular Tubes: Suitable for architectural railings, steel structural frames, and support frameworks for mechanical equipment.
3. Hexagonal and Oval Tubes: Custom decorative profiles, commonly used for stair handrails, furniture, and landscape design projects.
4. Custom Special-Shaped Tubes: We can manufacture D-shaped tubes, half-round tubes, grooved tubes, and other non-standard, irregular-cross-section tubes according to customer drawings.

Our product range covers a wide range of sizes, from small precision capillary tubes to large-diameter industrial pipes, encompassing both thin-walled decorative tubes and thick-walled, pressure-resistant industrial pipes.

Common Material Grades

• 201, 202: Economy grades with higher manganese content and lower cost, suitable for light-duty, dry applications.
• 304/304L: Mainstream austenitic stainless steel with a natural passivation layer on the surface that repels moisture and weak acidic or alkaline media. They are resistant to rust and discoloration during long-term use.
• 316/316L Stainless Steel: The 316 series, enhanced with molybdenum, offers improved corrosion resistance and is suitable for marine and high-chloride environments.
• 321: A high-temperature-resistant stainless steel capable of continuous operation below 700°C and intermittent use up to 850°C. Suitable for heat exchangers and exhaust pipes.
• 310S: A high-chromium, high-nickel austenitic stainless steel capable of continuous operation up to 1150°C and short-term exposure up to 1200°C, offering resistance to high-temperature oxidation and creep.

Performance Reference Table

Grade	Yield Strength (MPa)	Tensile Strength (MPa)	Elongation (%)	Hardness (HB)
304/304L	≥205	≥520	≥40	≤201
316/316L	≥210	≥520	≥40	≤217
321	≥205	≥520	≥40	≤217
310S	≥205	≥520	≥40	≤187
201	≥275	≥520	≥35	≤241

Features

• Corrosion Resistance and Durability: All grades offer higher oxidation resistance than galvanized pipes, significantly extending their service life in outdoor or humid environments.
• High Precision and Aesthetic Appeal: Welded pipes feature tighter tolerances and a dent-free surface. Compared to seamless stainless steel pipes of the same specifications, they offer a 20% reduction in overall costs and shorter lead times.
• Processing Versatility: With moderate toughness, these pipes can easily undergo secondary processing such as bending, flaring, reducing, and laser cutting. They support various surface treatments, including acid pickling to achieve a bright finish and internal and external polishing, with no harmful substances leaching from the welds.
• Flexible Customization: We can organize production according to different standards—including Chinese National Standards (GB), American Standards (ASTM), Japanese Industrial Standards (JIS), German Standards (DIN), and European Standards (EN)—based on customer requirements.

Applications

1. Fluid Conveyance Industry

Pure water pipelines, oil or chemical transport equipment in petrochemical plants, seawater desalination equipment, boiler equipment, and water pipes for mobile food trucks.

2. Food and Pharmaceutical Industries

Food-grade safety assurance; used for production line transport pipelines, such as those for alcoholic beverages, food, beverages, or instrumentation and machinery piping in pharmaceutical facilities.

3. Architectural & Decorative

Stair railings, safety guardrails, roadside landscaping, decorative tubing for hotels and home interiors, as well as automotive exhaust pipes, hydraulic tubing, and pneumatic tubing.

4. Power and Energy

Photovoltaic systems, nuclear power, wastewater treatment, high-temperature exhaust pipes, and 316L material for offshore engineering piping.

Welding Processes

The main welding processes commonly used for stainless steel welded tubes include TIG welding, high-frequency welding (HFW), and plasma welding. Among these, HFW tubes and TIG-welded tubes are the most widely used.

• High-frequency welding (HFW): A subcategory of resistance welding (ERW), it offers the lowest cost and fastest speed, though it may result in extrusion burrs on the inner wall of the tube. It is suitable for mass production of thin-walled tubes.
• TIG Welding: Offers high weld quality and is suitable for thin- to medium-walled stainless steel tubes.
• Plasma Welding: A welding process for medium- to thick-walled stainless steel tubes, often used in combination with TIG welding.
• Laser Welding: Primarily used for ultra-thin-walled or thin-walled precision stainless steel tubes; this technology is less widely adopted than TIG and HFW.

Comparison of Process Prices

Welding Process	Cost Level
HFW	Low
TIG	Medium
Plasma Welding	High
Laser Welding	Highest

Why Choose Glory Steel?

• Custom Material Options: Full range of 201, 304, 316L, 321, and duplex steel grades available in stock;
• Custom Specifications: Non-standard diameters, special wall thicknesses, extended lengths, and SCH thick-walled series;
• Processing Services: Cutting, polishing, beveling, flanging, threading, bending, and welding;
• Packaging Solutions: Plastic end caps + woven bags / wooden crates, with corrosion-resistant packaging for overseas export.

Glory Steel factory, located in Tianjin, China, is an ISO 9001, ISO 14001, and CE certified factory with an annual output of 100,000 tons. We specialize in manufacturing stainless steel welded pipes in a wide range of wall thicknesses and diameters, covering all cross-sectional shapes and surface finishes. With our high-quality products and services, we export to over 120 countries.