Stainless Pipe Supplier | 304/316 Grades, Custom Sizes – Chewit China

Buying stainless pipe from an overseas factory is not just about price. Importers, contractors, and OEM buyers need a supplier who can deliver the right grade, correct dimensions, and consistent quality, shipment after shipment. Chewit is a stainless pipe manufacturer based in Zhangjiagang, China, producing seamless steel pipe and welded pipe in carbon, alloy, and stainless steel pipe for buyers across North America, Europe, the Middle East, Asia-Pacific, South America, and Africa.
This guide explains what a stainless pipe is, which grades and standards matter, how to choose between seamless and welded construction, and what to check before you place an order. Whether you are a distributor stocking standard sizes or a project contractor sourcing custom stainless pipe for a specific application, this page gives you the practical information you need before sending an inquiry.

What Is a Stainless Pipe? (Definition & Key Properties)

 
A stainless pipe is a hollow steel product made from stainless steel alloy, used mainly to transport liquids, gases, or steam under pressure. Unlike a stainless steel tube, a pipe's size is described by nominal pipe size (NPS) and schedule (wall thickness), which follow standardized dimension tables rather than exact outside diameter.
The defining property of stainless pipe is its chromium content, usually 10.5% or higher, which forms a thin oxide layer on the surface. This layer protects the metal from rust, staining, and corrosion, even in wet, acidic, or salty environments. Depending on the grade, stainless pipe also offers:
  • Good weldability and formability
  • Resistance to high and low temperatures
  • Long service life with low maintenance
  • A clean, hygienic surface suitable for food and pharmaceutical use
Because of these properties, stainless pipe is widely used across construction, energy, marine, chemical processing, and food and beverage industries.

Stainless Pipe Grades We Supply: 304, 304L, 316, 316L

 
Choosing the correct grade affects both performance and cost. Chewit supplies stainless pipe in the following commonly requested grades:
  • 304 – The most widely used austenitic grade, offering good corrosion resistance and formability for general industrial and architectural use.
  • 304L – A low-carbon version of 304, better suited to welded applications where carbide precipitation must be avoided.
  • 316 – Contains molybdenum for improved resistance to chlorides and industrial chemicals, common in marine and chemical environments.
  • 316L – The low-carbon version of 316, preferred for welded pipe used in more aggressive corrosive conditions.

Grade	Key Alloying Element	Corrosion Resistance	Typical Applications
304	18% Cr / 8% Ni	Good	Architecture, food equipment, general industry
304L	18% Cr / 8% Ni, low carbon	Good	Welded pipe, sanitary equipment
316	16% Cr / 10% Ni / 2% Mo	Very good	Marine, chemical, pharmaceutical
316L	16% Cr / 10% Ni / 2% Mo, low carbon	Very good	Welded pipe in corrosive service

If you are unsure which grade fits your project, share your application details with our sales team and we can recommend a suitable option.

Seamless vs Welded Stainless Pipe – Which One Do You Need?

Stainless pipe is produced by one of two main methods, and the right choice depends on your application, budget, and pressure requirements.
Seamless stainless pipe is made by piercing a solid billet, so it has no weld seam. This construction gives it more uniform strength around the circumference, making it a common choice for high-pressure lines, hydraulic systems, and critical process piping.
Welded stainless pipe is formed by rolling flat strip into a cylinder and welding the seam, then finishing to the required dimensions. It generally costs less than seamless pipe and is widely used for structural work, low-to-medium pressure fluid transport, decorative fittings, and general fabrication.
For buyers, the decision often comes down to: seamless pipe for pressure-critical or safety-critical applications, and welded pipe when cost efficiency matters more than pressure rating. Let us know your operating pressure and application, and we can help you select the right construction type.

Stainless Pipe Sizes, OD, Wall Thickness & Custom Dimensions

Every project has different dimensional requirements, so Chewit produces stainless pipe to customer specifications rather than a fixed catalogue only. We can work from your drawing, sample, or reference standard to match:
  • Outside diameter (OD) and nominal pipe size (NPS)
  • Wall thickness / schedule (SCH)
  • Cut length or coil-fed continuous lengths
  • Tolerances required for your application
For buyers who are not yet sure of exact specifications, our team can also recommend standard sizes commonly used in your target industry, based on the application you describe. Sending us your intended use, working pressure, and installation environment helps us propose practical dimensions and avoid unnecessary cost from over-specifying wall thickness.

Manufacturing Standards We Follow (ASTM A312, ASTM A213, DIN, JIS, GB)

International buyers usually require stainless pipe manufactured to a recognized standard, so the product can be verified, inspected, and approved by their own engineers or third-party inspectors. Depending on your project and destination market, Chewit can work to standards such as:
  • ASTM A312 – Seamless and welded austenitic stainless steel pipe
  • ASTM A213 – Seamless stainless steel tube for boilers, superheaters, and heat exchangers
  • DIN – Common European dimensional and material standards
  • JIS – Japanese Industrial Standards, widely referenced across Asia
  • GB – Chinese national standards
If your project specifies a particular standard, tell our sales team when you send your inquiry so we can confirm feasibility and provide the relevant documentation with your order.

Surface Finish Options: BA, AP, EP.

Surface finish affects both appearance and performance, so we offer several finishing options for stainless pipe:
AP‑annealed and pickled pipe
After annealing and pickling, it has a matte silver-white appearance with high cost-performance ratio.  
Roughness Ra > 0.6μm; no need for high gloss finish.  
Applicable to water supply and drainage systems, general chemical fluids, steel structures, and standard mechanical applications.

BA‑polished annealed pipe
Polished under hydrogen protective atmosphere; no pickling required.  
The surface is smooth and shiny, with a clean inner wall without any pickling residues. Ra: 0.6μm; better corrosion resistance than the AP type.  
Applicable to water pipes, food-grade pipes, heat exchange equipment, pneumatic/hydraulic pipelines, and precision mechanical components.

EP‑electrolytic polished pipe
Electrochemical polishing is performed on the BA pipe, resulting in a mirror-like finish.  
Microscopic burrs on the inner wall are removed; Ra ≤ 0.2μm. The inner wall does not easily accumulate deposits or scaling, and the passivation layer is dense, ensuring excellent corrosion resistance and cleanliness.  
Applicable to highly clean and demanding environments such as biomedical applications, high-purity gases, semiconductors, and ultra-pure fluids.

Applications of Our Stainless Pipes

Stainless pipe from Chewit is used across several industries, including:
  • Construction – Structural framing, railings, staircases, curtain wall support, and architectural features
  • Food & Beverage – Piping for processing equipment, sanitary lines, and hygienic installations
  • Chemical Processing – Transport of corrosive fluids and chemical-resistant piping systems
  • Marine – Deck fittings, piping, and structural components exposed to salt water and humidity
Because buyer requirements vary widely by industry, we recommend describing your specific application when you contact us, so we can confirm the most suitable grade, wall thickness, and finish for your project.

Why Choose Chewit as Your Stainless Pipe Supplier in China

Chewit is based in Zhangjiagang, Jiangsu Province, and has supplied precision steel pipe and tube to international buyers for more than a decade. A few reasons overseas buyers choose to work with us:
  • Experience producing seamless steel pipe in carbon, alloy, and stainless steel for industrial and hydraulic applications
  • One factory covering multiple related product lines, so buyers with mixed requirements can consolidate sourcing
  • Support for custom sizes, grades, and finishes rather than fixed catalogue-only production
  • Export experience shipping to buyers across North America, Europe, the Middle East, Asia-Pacific, South America, and Africa
If your sourcing needs extend beyond stainless pipe, we also produce hydraulic pipe and tube for fluid power systems, and
aluminum telescopic pole products for outdoor and equipment applications, so returning buyers can often source multiple product lines from a single supplier.

Our Manufacturing Process – From Raw Coil to Finished Pipe

 
Producing stainless pipe involves several controlled steps to ensure the final product meets dimensional and material requirements:
  • Raw material selection – Stainless steel coil or billet is checked against required grade and chemical composition
  • Forming – Coil is slit and formed for welded pipe, or billet is pierced for seamless pipe
  • Welding or piercing – Welded pipe seams are joined and inspected; seamless pipe is pierced and elongated
  • Heat treatment – Annealing relieves stress and restores corrosion resistance affected by forming or welding
  • Sizing and straightening – Pipe is drawn or rolled to final dimensions and straightened
  • Surface finishing – Pipe is polished, brushed, or treated according to the specified finish
  • Cutting and inspection – Pipe is cut to length and checked for dimensions, surface quality, and defects

Quality Control & Certifications

Every order goes through inspection before shipment. Our quality process typically includes:
  • Incoming material verification against grade and chemical composition requirements
  • In-process dimensional checks during forming and sizing
  • Surface inspection for finish, scratches, and weld quality
  • Final dimensional and visual inspection before packing
We can provide a mill test certificate (MTC) with your order, confirming material grade and key test results. If your project requires third-party inspection or additional documentation, let us know at the inquiry stage so we can plan accordingly.

Custom Stainless Pipe Fabrication & OEM Services

Beyond standard stainless pipe, we support additional fabrication and OEM services for buyers who need a more finished product:
  • Cutting to specific lengths
  • End finishing (plain end, beveled end)
  • Polishing to a specified finish grade
  • Bending or forming to customer drawings, where feasible
  • Custom packaging and labeling for OEM and private-label buyers
If you are developing your own branded product line or need pipe finished to a specific spec before it reaches your customer, share your requirements and we will confirm what is possible for your order size.

Minimum Order Quantity, Lead Time & Bulk Pricing

MOQ, lead time, and pricing for stainless pipe depend on grade, size, wall thickness, and finish, since these affect raw material sourcing and production scheduling. As a general guide:
  • Smaller MOQs are usually possible for standard sizes and grades already in production
  • Custom sizes, non-standard grades, or special finishes typically require a higher MOQ due to setup and material minimums
  • Lead time depends on order complexity and current production schedule
For an accurate MOQ, lead time, and price quotation, send us your required grade, size, quantity, and finish, and we will respond with specific figures for your order.

Packaging, Shipping & Export Capabilities

Export packing is designed to protect stainless pipe from scratches, moisture, and transit damage. Depending on size and destination, we typically use:
  • Bundling with protective wrap or plastic end caps
  • Waterproof packaging for sea freight
  • Wooden crates or pallets for larger or heavier orders
  • Clear labeling for grade, size, and quantity per shipping requirements
We prepare export documentation for international shipments and can work with FOB, CIF, or other terms based on your logistics arrangement. Tell us your destination port and preferred shipping method when requesting a quotation.

Stainless Pipe vs Stainless Tube – What's the Difference?

Buyers often use "pipe" and "tube" interchangeably, but they are technically different products:
  • Stainless pipe is sized by nominal pipe size (NPS) and schedule, mainly used to transport fluids and gases under pressure. Its actual outside diameter does not always match its nominal size.
  • Stainless steel tube is sized by actual outside diameter and wall thickness, and is commonly used for structural, mechanical, or precision applications where exact dimensions matter more than flow capacity.
If your project involves structural framing, precision equipment, or exact dimensional tolerances rather than fluid transport, our stainless steel tube range may be a better fit than standard pipe. Let us know your intended use and we can recommend the correct product type.

Frequently Asked Questions About Stainless Pipe

What is the difference between 304 and 316 stainless pipe?

316 contains molybdenum, which improves resistance to chlorides and industrial chemicals compared to 304. 316 is generally preferred for marine and chemical environments, while 304 works well for general industrial and architectural use.

Can you provide stainless pipe in custom sizes and lengths?

Yes. We produce stainless pipe to customer specifications, including custom OD, wall thickness, and cut length, based on your drawing or reference standard.

What is the standard lead time for a stainless pipe order?

Lead time depends on grade, size, quantity, and finish. Standard sizes already in production generally ship faster than custom specifications. Share your order details and we will confirm a specific lead time.

Do you provide mill test certificates?

Yes, we can provide a mill test certificate confirming material grade and key test results with your order.

What is your minimum order quantity (MOQ)?

MOQ varies by grade, size, and finish. Standard specifications typically have lower MOQs than custom orders. Contact us with your requirements for an exact figure.

Can Chewit produce stainless pipe according to my own drawing?

Yes. Send us your drawing or specification, and our team will confirm feasibility, pricing, and lead time before production begins.

Conclusion

Sourcing stainless pipe from a Chinese manufacturer works best when your supplier understands your application, offers the right grade and standard, and communicates clearly about lead time and quality documentation. Chewit has supplied stainless, carbon, and alloy steel pipe and tube to buyers across multiple regions for more than a decade, and we are set up to handle both standard orders and custom specifications.
If you are comparing suppliers or preparing a specification for a new project, send us your required grade, size, and application details. Our team can confirm feasibility, provide a quotation, and arrange samples where needed. Contact our sales team to discuss your stainless pipe requirements and get started on your order.