# SUS 347 and UNS S34700: How to Check a Pipe Designation

Canonical: https://jundapipe.com/en-CA/blog/sus347-uns-s34700-designation-check

Separate grade names from product standards when reviewing SUS 347 and UNS S34700. Includes a designation cross-check and discrepancy workflow.

A request written as “SUS 347 / UNS S34700” needs a product standard and edition before it becomes an unambiguous pipe order. A grade designation identifies a material within a naming system; it does not by itself establish dimensions, heat treatment, inspection or acceptance under another system.

[IMOA’s austenitic reference table](https://www.imoa.info/molybdenum-uses/molybdenum-grade-stainless-steels/austenitic-stainless-steel.php) associates 347 with UNS S34700. That is useful background for the UNS designation. It does not verify a complete JIS-to-ASTM equivalence or demonstrate that a particular pipe complies with both.

## What four fields should be compared?

| Field                                | Document to check                            | Question to resolve                                         |
| ------------------------------------ | -------------------------------------------- | ----------------------------------------------------------- |
| Full material designation            | Drawing and purchase specification           | Are prefixes, suffixes and grade symbols complete?          |
| Product standard                     | Controlled standard and project requirements | Does it cover the required pipe or tube form?               |
| Edition and amendments               | Order and certificate                        | Are the same requirements being applied?                    |
| Supply and verification requirements | Technical offer and inspection plan          | What condition, dimensions, tests and records are required? |

Keep the requested designation and the proposed designation in separate columns. Do not replace one with the other merely to make the documents look consistent.

## Why does pipe versus tube matter here?

[ASTM A312/A312M-25](https://store.astm.org/a0312_a0312m-25.html) is a pipe specification that discusses TP347 and its H modification in the context of high-temperature and general corrosive service. [ASTM A213/A213M-25](https://store.astm.org/a0213_a0213m-25.html) has a different product scope: seamless boiler, superheater and heat-exchanger tubes.

An equivalence table focused on chemistry can miss these product requirements. A buyer seeking a Japanese-standard tube needs the exact applicable JIS product designation, not only a short material-family name copied from a search query. Verify it from the controlled JIS document and the project’s acceptance rules.

## What if the drawing and certificate use different names?

First identify whether the difference is formatting, a naming-system difference or an actual material departure. Obtain the supplier’s written explanation. Then compare the relevant requirements using the complete standards, including chemistry, condition and required tests.

If dual compliance is claimed, ask for explicit documentary support for both specifications. If compliance with only one is claimed, treat the other as a proposed substitution and route it for engineering approval. Preserve the original drawing designation and the approved deviation record so later inspections can reconstruct the decision.

A useful closeout statement identifies the drawing revision, order line, accepted specification, certificate reference and approving role. “Equivalent material” without those details leaves the same ambiguity for the next reviewer.

## What does Junda’s catalogue establish?

Junda’s [347H product page](https://jundapipe.com/products/347h-seamless-stainless-steel-pipe) establishes that this product name appears in its range. [Catalogue source](https://jundapipe.com/products) It does not, by itself, confirm SUS 347, a specific JIS suffix, dual certification or origin in Japan.

Send the original requirement and any proposed alternative through the [contact page](https://jundapipe.com/contact). Ask Junda to respond using the exact product standard and designation. For the separate issue of H-grade substitution, use the [347 versus 347H review](https://jundapipe.com/blog/347-vs-347h-stainless-steel-pipe).