ASTM A554 TP316L Welded Square/Rectangular Tube
Nov 07, 2025
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ASTM A554 TP316L welded stainless steel rectangular tube is a welded mechanical tubing product conforming to ASTM A554, made from a low-carbon 316L stainless steel (UNS S31603, W.Nr 1.4404/1.4435) and formed into rectangular or square shapes.
Note: ASTM A554 covers welded stainless steel mechanical tubing only - seamless equivalents are specified under ASTM A312 or A269
ASTM A554 TP316L welded stainless steel is manufactured from flat-rolled steel using automated precision welding (typically TIG welding without filler materials). The "L" designation indicates low carbon content (C ≤0.035%), enhancing corrosion resistance, particularly in harsh environments, and making the tubing not prone to sensitization. Sizes are available up to 16 inches with wall thicknesses greater than 0.51 mm; the product can be cut, chamfered and threaded on site and customized into square, round and rectangular shapes
Specification of ASME SA554 Gr 316L Tubing
| Standards Specification | ASME SA554 TP316L Tube |
| Manufacturing Type | DOM / Welded / Seamless / Fabricated / ERW / CDS / CDW / CEW |
| Surface Finish | polished 320 grit, Mill finish, Polished 180 grit |
| Wall Thickness in Inch | 0.049 - 0.375 Inch |
| Sizes in Inch | ½ - 8 Inch Diameter |
| Standard | JIS, ASTM, EN, SUS, AISI, GB, DIN |
| Service | Decoiling, Bending, Punching, Welding, Cutting, Moulding |
| Technique | Cold rolled, Cold drawn, Hot rolled, Extrusion Tube |
ASTM A554 316L Chemical Composition
| Grade | C | Mn | Si | P | S | Cr | Mo | Ni | N | |
| ASTM A554 316L | min. | – | – | – | – | – | 16.0 | 2.0-3.0 | 10.0 | – |
| max. | 0.035 | 2.0 | 0.75 | 0.045 | 0.03 | 18.0 | 14.0 | – | ||
ASTM A554 316L Mechanical Properties
| Grade | Tensile Strength (MPa) min | Yield Strength 0.2% Proof (MPa) min | Elongation (% in 50mm) min | Hardness | |
| Rockwell B (HR B) max | Brinell (HB) max | ||||
| ASTM A554 316L | 485 | 170 | 40 | 95 | 217 |
ASTM A554 316L Physical Properties
| Grade | Density (kg/m3) | Elastic Modulus (GPa) | Mean Coefficient of Thermal Expansion (m/m/0C) | Thermal Conductivity (W/m.K) | Specific Heat 0-1000C (J/kg.K) | Electrical Resistivity (n.m) | |||
| 0-1000C | 0-3150C | 0-5380C | at 1000C | at 5000C | |||||
| ASTM A554 316L | 8000 | 193 | 15.9 | 16.2 | 17.5 | 16.3 | 21.5 | 500 | 740 |
SS316L Equivalent Grade
| TANDARD | WERKSTOFF NR. | UNS | JIS | BS | GOST | AFNOR | EN |
| SS 316L | 1.4404 / 1.4435 | S31603 | SUS 316L | 316LS11 / 316LS13 | 03Ch17N14M3 / 03Ch17N14M2 | Z3CND17‐11‐02 / Z3CND18‐14‐03 |
X2CrNiMo17-12-2 / X2CrNiMo18-14-3 |
ASTM A554 Steel Tube Weight Chart
|
OD Size, in. (mm) |
OD, ±in. |
mm |
ID, ±in. |
mm |
|
Up to 3⁄32 (2.4), excl |
0.001 |
0.03 |
0.001 |
0.03 |
|
3⁄32 to 3⁄16 (2.4 to 4.8), excl |
0.0015 |
0.038 |
0.0015 |
0.038 |
|
3⁄16 to 1⁄2 (4.8 to 12.7), excl |
0.003 |
0.08 |
0.005 |
0.13 |
|
1⁄2 to 1 (12.7 to 25.4), excl |
0.004 |
0.10 |
0.006 |
0.15 |
|
1 to 11⁄2 (25.4 to 38.1),excl |
0.005 |
0.13 |
0.007 |
0.18 |
|
1 1⁄2 to 2 (38.1 to 50.8),excl |
0.006 |
0.15 |
0.008 |
0.20 |
|
2 to 2 1⁄2 (50.8 to 63.5),excl |
0.007 |
0.18 |
0.010 |
0.25 |
|
2 1⁄2 to 3 1⁄2 (63.5 to 88.9),excl |
0.010 |
0.25 |
0.014 |
0.36 |
|
3 1⁄2 to 5 (88.9 to 127.0),incl |
0.015 |
0.38 |
0.020 |
0.51 |
|
Over 5 to 16 (127.0 to 406.4), incl |
0.00125 in./in. or mm/mm of cir-cumference |
0.0013 in./in. or mm/mm of cir-cumference |
||
Application of SS316L:
1.Coastal & Marine Architecture (Key Application)
Seaside handrails, balcony balustrades, stair guardrails, facade trim, coastal landscape components. Molybdenum provides excellent chloride‑salt corrosion resistance for long‑term coastal service, outperforming 304.
2.Architectural & Municipal Decoration
Outdoor sign supports, canopy frames, public street furniture, partition frames, shop display structures. Available in No.4 hairline, mirror polish finishes with tight squareness and straightness tolerance.
3.Machine Frames & Structural Components
Frames for food‑processing and pharmaceutical equipment, seawater‑exposed support structures, laboratory equipment frames, corrosion‑resistant machine bases. Low‑carbon 316L minimizes intergranular corrosion after field welding.
4.Swimming Pool & Spa Facilities
Pool fences and spa enclosure structures, resistant to chlorine‑induced pitting corrosion.
5.Outdoor Industrial Structures
Open‑air structural frames in chemical plants, outdoor supports exposed to de‑icing salt.
⚠️Note: ASTM A554 covers welded mechanical tubing NOT for pressure piping. For pressure fluid service, specify ASTM A312 instead.
Coastal & Marine Architecture
Machine Frames & Structural Components
Outdoor Industrial Structures
ASME A554 Steel Tubing Price List
exporter of TP316L welded pipe
GNEE is an ISO-certified exporter of TP316L welded pipe. As a distributor of ASTM A554 stainless steel pipe, our A554 TP304 seamless pipes are tested according to international standards and specifications such as DIN, JIS, EN, and ASTM. We maintain a large inventory, supplying to over 60 countries, and offer comprehensive after-sales service and fast delivery.Email: sales@gneestainless.com
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FAQ
Can ASTM A554 TP316L square / rectangular tube be used for pressure fluid transportation?
No. ASTM A554 covers welded mechanical tubing without pressure rating, only for structural & architectural usage such as handrails, frames and supports. For pressure fluid service, specify ASTM A312 pipe instead.
Is the weld seam prone to rust on A554 welded square tube?
Qualified tubes have weld bead removed and passivated. Weld zone is still the weak point for corrosion. Extra passivation treatment is recommended for heavy salt‑spray environments.
Will TP316L A554 tube never rust in coastal areas?
No. TP316L performs much better than 304 under chloride atmosphere, but pitting corrosion may still occur under permanent seawater immersion. It suits salt‑spray atmosphere, not continuous seawater immersion.
How to distinguish ASTM A554 and ASTM A312 for selection?
ASTM A554: mechanical & architectural structural tubing (square / rectangular), no pressure rating. ASTM A312: pressure‑rated fluid pipe, mainly round pipe.
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