Welded Stainless Steel Square Pipe
Longitudinally welded square hollow section in austenitic duplex and ferritic stainless grades
Specifications
Stainless Steel Pipe, Steel Pipe
Seamless Stainless Steel Rectangle Pipe Without a Weld Seam
Rectangular hollow section drawn from a pierced tube so there is no longitudinal seam
Seamless stainless steel rectangle pipe is a rectangular hollow section shaped from a pierced and drawn mother tube, so the finished member carries no longitudinal weld line, and it is produced to EN10216, ASTM A312 or JIS G3463 in grades from 304 and 316L to 310S, 2205 and 904L. Hydraulic equipment builders, pressure part fabricators and inspection engineers ask for the seamless route when a code, a fatigue duty or a corrosive service will not accept a weld seam running the length of the part. Specifying the section without a seam removes the seam examination, the seam orientation note on the drawing and the argument about weld zone corrosion that follows a welded section through approval. Orders begin at 1 ton and a free sample can be released for grade and dimensional checking beforehand.
- Product Name — Seamless Stainless Steel Rectangle Pipe
- Section Shape — Rectangular hollow section
- Technique — Seamless
- Standard — EN10216 ASTM A312 JIS G3463
- Material Grades — 201 202 301 304 304L 309S 310S 316 316Ti 316L 410 430 2205 904L
Why It Is Specified
Key Benefits of Seamless Stainless Steel Rectangle Pipe
No Longitudinal Seam to Examine or Orient
There is no weld line along the member, so drawings do not need a seam position note and inspection does not need to trace a seam through the assembly.
Uniform Structure Around the Whole Section
Because the section is drawn from a pierced tube, the metallurgical structure is continuous around the perimeter. There is no heat affected zone waiting to become the corrosion or fatigue starting point.
Suits Pressure and Cyclic Load Duty
Seamless is the usual requirement where internal pressure or repeated loading applies. The absence of a seam removes the weakest line in a welded rectangular member.
Section Dimensions Made to Drawing
Width, depth, wall thickness and length are customized. The part is drawn to the size the design needs rather than machined down from a nearest stock section.
Corrosion Grades Through to 2205 and 904L
304, 304L, 316, 316Ti, 316L, 310S, 2205 and 904L are all available in the seamless route so the grade can follow the process fluid rather than the supply.
Certification Set of ISO9001 BV SGS and RoHS
The stated certification covers ISO9001, BV, SGS and RoHS. Ask for the mill test certificate so the heat and grade are documented for the pressure file.
Problems It Solves
What This Material Removes From Your Process
Weld Seams Rejected by the Inspection Authority
Some code work and some client specifications simply do not accept a longitudinal seam in a rectangular member. Supplying seamless removes the concession request from the approval route.
Corrosion Starting at the Heat Affected Zone
In chloride and acid service the weld zone of a welded section pits before the parent metal. A drawn seamless section has no such zone to protect.
Fatigue Cracking Along a Longitudinal Weld
Cyclically loaded members can initiate a crack at the seam. Removing the seam removes that initiation site from the design.
Machining Into a Section That Was Not Sized for It
Machining a stock section down to the required wall wastes metal and time. A customized seamless section arrives close to the finished dimension.
Committing Tonnage Without Seeing the Material
A free sample can be released and the order starts at 1 ton, so dimensional and grade checks can be done before a full order is placed.
Application Scenarios
Where It Is Used
Hydraulic and Pneumatic Equipment Bodies
Rectangular members used as manifold bodies, cylinder housings and load bearing arms where internal pressure rules out a seam.
Pressure Part Fabrication and Code Work
Components inside pressure assemblies where the inspection authority requires seamless material for the rectangular element.
Chemical and Petrochemical Structural Elements
Supports and members inside process units in 316L, 2205 and 904L where a weld seam would be the first line to suffer pitting.
High Temperature Equipment Frames
310S and 309S rectangular members around furnace and heat treatment equipment operating in scaling conditions.
Precision Machine Structures
Rectangular members machined into fixtures and load frames where a consistent wall around the section keeps the finished part predictable.
Marine and Offshore Support Members
Duplex 2205 sections for supports exposed to salt spray where crevice corrosion at a seam would shorten the service life.
Who It Is For
Buyers Who Specify This Product
- Hydraulic equipment builders buying seamless rectangular bodies for manifolds and cylinder housings
- Pressure part fabricators buying seamless section where a welded member will not pass inspection
- Petrochemical maintenance engineers buying 316L and 904L members for corrosive process units
- Heat equipment makers buying 310S rectangular section for furnace surrounds
- Machine tool and fixture shops buying sections that will be machined after delivery
- Offshore and marine contractors buying duplex 2205 supports for salt spray exposure
Technical Data
Specifications and Technical Features
Values below come from the product data published by Shandong Tianyu Metal Products. Confirm the exact grade and size against your order.
| Product Name | Seamless Stainless Steel Rectangle Pipe |
|---|---|
| Section Shape | Rectangular hollow section |
| Technique | Seamless |
| Standard | EN10216 ASTM A312 JIS G3463 |
| Material Grades | 201 202 301 304 304L 309S 310S 316 316Ti 316L 410 430 2205 904L |
| JIS Designations | SUS304 SUS304L SUS321 SUS316 SUS316L SUS309S SUS310S |
| EN Material Numbers | 1.4372 1.4373 1.4301 1.4833 1.4845 1.4401 1.4571 1.4404 |
| Size | Customized |
| Delivery | Within 7-10 working days after receiving the deposit or according to order quantity |
| Minimum Order | 1 ton or free sample |
| Certification | ISO9001 BV SGS RoHS |
| Price Term | TT or LC |
| Place of Origin | China |
Technical Features
- Seamless rectangular hollow section drawn from a pierced mother tube
- Standards EN10216 ASTM A312 and JIS G3463
- Grades 201 202 301 304 304L 309S 310S 316 316Ti 316L 410 430 2205 and 904L
- JIS designations SUS304 SUS304L SUS321 SUS316 SUS316L SUS309S and SUS310S
- EN material numbers 1.4301 1.4372 1.4373 1.4401 1.4404 1.4571 1.4833 and 1.4845
- Width depth wall thickness and length customized to drawing
- No longitudinal weld seam in the finished section
- Certification ISO9001 BV SGS and RoHS
Materials
- Austenitic 304 304L 316 316L and stabilized 316Ti for general corrosive duty
- Heat resistant 309S and 310S for scaling service
- Duplex 2205 for chloride bearing and marine exposure
- Super austenitic 904L for acid service
- Ferritic 430 and martensitic 410 for dry and wear related details
Certification
- ISO9001
- BV
- SGS
- RoHS
Manufacturing
How It Is Made and Processed
Piercing the billet to produce a hollow mother tube
Hot and cold drawing the tube to the required wall
Forming the round tube into the rectangular profile through shaping passes
Solution annealing and pickling to restore the corrosion resistant surface
Sizing and straightening to the ordered width and depth
Cutting to length and deburring the ends
Marking bundling and export packing
Quality Control
Checks Before It Ships
- Grade checked against the nominated EN ASTM or JIS designation
- Wall thickness measured at each corner and face of the section
- Width depth and squareness verified against the ordered dimensions
- Surface examined for drawing marks and pickling condition
- Straightness and cut length confirmed before packing
- Heat identity carried through to the mill test certificate
Customization
What We Can Change on Your Order
- Rectangular section width depth and wall drawn to your drawing
- Cut lengths supplied against your part list
- Grade nominated from 304 316L 310S 2205 or 904L
- Standard supplied as EN10216 ASTM A312 or JIS G3463
- Free sample for dimensional and grade checking before the order
- Packing and marking arranged to suit the receiving inspection process
Comparison
Seamless Stainless Steel Rectangle Pipe Against the Alternatives
| Welded stainless rectangle pipe | There is no longitudinal seam to examine, orient or protect, which is what pressure and cyclic load duty usually requires. |
|---|---|
| Machined solid stainless bar | A drawn hollow section arrives near the finished wall, so there is far less metal to remove and far less swarf to pay for. |
| Fabricated box section from plate | A drawn section has no corner welds to grind, inspect or passivate, and the wall stays continuous around the perimeter. |
| Seamless stainless round pipe | Flat faces allow direct clamping, machining and flush mounting where a round tube would need a saddle or a fixture. |
Use Guide
Specifying Handling and Welding Notes
- State the wall tolerance you need at the corners if the section is to be machined after delivery
- Specify seamless where the inspection body or client specification excludes a longitudinal weld
- Keep 2205 within its recommended temperature band and use 310S where the duty is genuinely hot
- Use matched filler and a controlled heat input when welding the section into an assembly
- Repassivate any surface that has been machined or ground before the part enters corrosive service
- Send the part drawing with width depth wall and length so the section arrives close to finished size
Questions Buyers Ask
Seamless Stainless Steel Rectangle Pipe FAQ
How is a seamless rectangular section actually made?
It starts as a pierced and drawn round mother tube which is then shaped into the rectangular profile, so the finished section carries no longitudinal weld.
Do we need seamless or will a welded section do?
Welded is normally adequate for structural and frame duty. Choose seamless where internal pressure, cyclic loading or a client specification rules out a longitudinal seam.
Which standards can you certify the section to?
EN10216, ASTM A312 and JIS G3463. Nominate the one your drawing uses and ask for the mill test certificate with the shipment.
What is the smallest order you will produce?
1 ton is the minimum order, and a free sample can be released ahead of that for grade and dimensional checking.
Can the section be supplied in 2205 duplex?
Yes. 2205 and 904L are both in the grade range and are the usual choice for chloride bearing or acid duty.
When will the material be ready to ship?
Within 7-10 working days after the deposit is received, or according to the ordered quantity for a larger run.
Will the section be annealed and pickled?
Solution annealing and pickling are part of the route so the corrosion resistant surface is restored after drawing and forming.
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