ASTM A358
Electric-fusion-welded austenitic stainless pipe for high temperature
Covers electric-fusion-welded austenitic stainless steel pipe, typically in larger diameters, for high-temperature and corrosive service.
- Pipe & tube
- ASME SA-358
- 6 grades supplied to it
Reviewed by the Kanak Steel & Engineering Co. technical team · Updated October 2026
What is ASTM A358?
ASTM A358 is the specification for electric-fusion-welded (EFW) austenitic stainless steel pipe for high-temperature and general corrosive service. It is made from plate and is used for large diameters and heavy walls. Five classes set how the seam is welded and examined — Class 1 (double-welded with filler, fully radiographed) is the most common in process plants.
ASTM A358 at a glance
| Products | EFW pipe made from plate, usually NPS 8 and larger |
|---|---|
| Material | Austenitic stainless — 304L, 316L, 321, 347 and others |
| Classes | 1 to 5 — welding method and radiography |
| ASME designation | SA-358 |
ASTM A358 classes
| Class | Welding | Radiography |
|---|---|---|
| 1 | Double-welded with filler metal | 100% |
| 2 | Double-welded with filler metal | None |
| 3 | Single-welded with filler metal | 100% |
| 4 | As class 3, inside pass may be without filler | 100% |
| 5 | Double-welded with filler metal | Spot |
How to write ASTM A358 on a purchase order
Name the product, size, material specification and grade, the dimensional standard and the certificate. An example line:
Illustrative only — sizes, tests, inspection level and any project values come from your purchase specification.
ASTM A358 edition and verification status
Which edition we have confirmed, and what is still being checked before any numerical requirement is published here.
| Current edition | Not yet confirmed against the publisher listing |
|---|---|
| Full-text verification | In progress — numerical requirements are not published on this page |
| Edition on your order | The edition named in your purchase order or design code governs — confirm it with your enquiry |
What to know before ordering to ASTM A358
The points that decide whether material to ASTM A358 is accepted at inspection.
- Five classes (1 to 5) define whether filler metal is used and how much of the weld is radiographed.
- Class 1 — double-welded with filler and 100% radiography — is the most common in process plant.
- Use it when pipe sizes go beyond what A312 welded pipe mills produce.
Grades and products we supply to ASTM A358
| Grade | Product | Designation on the certificate |
|---|---|---|
| SS 304 | Pipe & Tube | ASTM A312 · A358 |
| SS 304L | Pipe & Tube | ASTM A312 · A358 |
| SS 310 / 310S | Pipe & Tube | ASTM A312 · A358 |
| SS 316 / 316L | Pipe & Tube | ASTM A312 · A358 |
| SS 321 | Pipe & Tube | ASTM A312 · A358 |
| SS 347 | Pipe & Tube | ASTM A312 · A358 |
How ASTM A358 fits into an order
A purchase order line is only complete when it names the material standard, the dimensional standard and the inspection document. Miss one and the mill, the inspector and the buyer can each read the order differently.
Standards used with ASTM A358
Same family
ASTM A358 — questions buyers ask
What is ASTM A358?
ASTM A358 is the specification for electric-fusion-welded (EFW) austenitic stainless steel pipe for high-temperature and general corrosive service. It is made from plate and is used for large diameters and heavy walls. Five classes set how the seam is welded and examined — Class 1 (double-welded with filler, fully radiographed) is the most common in process plants.
When is A358 used instead of A312?
For large-diameter or heavy-wall stainless pipe made from plate, beyond the practical range of seamless or A312 welded pipe.
Which A358 class should I order?
The one your piping class names; Class 1 (double-welded, fully radiographed) is the usual choice for pressure piping.
Which grades do you supply to ASTM A358?
SS 304, SS 304L, SS 310 / 310S, SS 316 / 316L, SS 321, SS 347 — see the table on this page for the exact product and designation.
What is the difference between ASTM A358 and ASME SA-358?
ASME SA-358 is the ASME Boiler and Pressure Vessel Code (Section II) adoption of ASTM A358. The technical requirements are usually identical to a specific ASTM edition; pressure-equipment codes call for the ASME designation, and most mill certificates show both.
Do you supply certificates to this standard?
Yes. Material is supplied with mill test certificates to EN 10204 3.1 showing the standard, grade and heat number; 3.2 with third-party inspection on request.
Sources: the ASTM / ASME specifications named on this page and producer datasheets · Last updated October 2026