UNS
A unified alphanumeric material designation. It identifies a composition family; it is not by itself a complete purchasing specification.
Reference scope
Compare designations without treating them as automatic substitutes
One material can appear under a common grade name, a UNS identifier, a European material number, a JIS designation, and one or more purchasing specifications. Those labels do not all serve the same purpose. UNS, EN and JIS can identify or classify a material; ASTM and ASME specifications also define requirements for a particular product form and use context.
This resource is a cross-reference layer between NPRO’s material families, individual grade references and broader tube sheet material standards. It does not choose a material for the process. For decision guidance based on fluids, temperature and corrosion mechanisms, use the tube sheet material-selection guide.
Use limitation: These are commonly encountered designation relationships, not permission to substitute one material for another. The project specification, applicable material standard, product form, purchase order, drawing and engineering approval remain controlling.
How to read the reference
Designation system versus product specification
Read across a row to identify a relationship, then verify the required chemistry, properties, condition, dimensions, testing and product form in the governing specification.
EN
European material numbers and names. A nearby EN designation may be comparable without being chemically identical to another regional grade.
JIS
Japanese designations used under the applicable JIS product standard. A dash means no relationship has been safely established here.
ASTM
Material specifications commonly scoped by form: plate/sheet, bar, forging, tube/pipe or another manufactured form.
ASME
Material specifications used in ASME Code contexts. The applicable SA/SB specification and edition must be confirmed; its presence here is not an NPRO certification claim.
Grade cross-reference
Common tube sheet material designations
The table separates material identifiers from product-form specifications. “Commonly comparable” means a useful cross-reference starting point, not an exact-equivalence or substitution statement.
For grade-specific context, compare NPRO’s 304 stainless steel reference with the low-carbon 304L stainless steel reference; their family relationship does not make them automatic substitutes.
On smaller screens, scroll the table horizontally. Row headers and qualification notes remain part of each comparison.
| Material / grade | NPRO family | UNS | EN / European designation | JIS | ASTM product-form reference | ASME reference / note | Important qualification | NPRO reference |
|---|---|---|---|---|---|---|---|---|
| 304 | Stainless steel | S30400 | 1.4301 | SUS304 | ASTM A240: plate, sheet and strip ASTM A182 F304: forgings | SA-240 / SA-182 may apply in the relevant ASME Code context. | COMMONLY COMPARABLE Confirm form, condition and specification edition. | SS304 grade page |
| 304L | Stainless steel | S30403 | 1.4307 | SUS304L | ASTM A240: plate, sheet and strip ASTM A182 F304L: forgings | SA-240 / SA-182 may apply in the relevant ASME Code context. | COMMONLY COMPARABLE Low-carbon 304-family designation; not a blanket substitute for 304. | SS304L grade page |
| 316 | Stainless steel | S31600 | 1.44011 | SUS316 | ASTM A240: plate, sheet and strip ASTM A182 F316: forgings | SA-240 / SA-182 may apply in the relevant ASME Code context. | COMMONLY COMPARABLE Do not flatten 1.4401 and higher-molybdenum 1.4436 into one identical designation. | SS316 grade page |
| 316L | Stainless steel | S31603 | 1.4404 | SUS316L | ASTM A240: plate, sheet and strip ASTM A182 F316L: forgings | SA-240 / SA-182 may apply in the relevant ASME Code context. | COMMONLY COMPARABLE Low-carbon 316-family designation; verify chemistry and form. | SS316L grade page |
| SS321 | Stainless steel | S32100 | 1.4541 | SUS321 | ASTM A240: plate, sheet and strip Forging specification: confirm ordered form. | SA-240 may apply for plate/sheet in the relevant ASME Code context. | COMMONLY COMPARABLE Titanium-stabilized stainless designation. | SS321 grade page |
| SS316Ti | Stainless steel | S31635 | 1.4571 | — | ASTM A240: plate, sheet and strip Forging specification: confirm ordered form. | SA-240 may apply for plate/sheet in the relevant ASME Code context. | RELATED DESIGNATION Do not infer a JIS designation without the governing JIS product standard. | SS316Ti grade page |
| Duplex 2205 | Duplex steel | S31803 / S322052 | 1.4462 | SUS329J3L | ASTM A240: plate, sheet and strip ASTM A182 F51 / F60: forgings | SA-240 / SA-182 may apply in the relevant ASME Code context. | 2205 FAMILY S31803 and S32205 are distinct UNS designations; confirm which is ordered. | Duplex 2205 grade page |
| Super Duplex 2507 | Super duplex | S32750 | 1.4410 | —3 | ASTM A240: plate, sheet and strip ASTM A182 F53: forgings | SA-240 / SA-182 may apply in the relevant ASME Code context. | COMMONLY ASSOCIATED No JIS value asserted; do not substitute catalogue look-alikes. | Super Duplex 2507 page |
| Monel 400 | Nickel / Monel | N04400 | 2.4360 | NW4400 | ASTM B127: plate, sheet and strip ASTM B564: forgings | ASME SB-127 / SB-564 may apply by product form and Code context. | COMMONLY COMPARABLE Product form determines the material specification. | Monel 400 grade page |
| Inconel 625 | Inconel | N06625 | 2.4856 | NCF625 | ASTM B443: plate, sheet and strip ASTM B564: forgings | ASME SB-443 / SB-564 may apply by product form and Code context. | COMMONLY COMPARABLE B443 and B564 are not interchangeable: they cover different forms. | Inconel 625 grade page |
| Hastelloy C-276 | Hastelloy | N10276 | 2.4819 | — | ASTM B575: plate, sheet and strip ASTM B564: forgings | ASME SB-575 / SB-564 may apply by product form and Code context. | COMMONLY ASSOCIATED Trade name, UNS and product specification each serve different roles. | Hastelloy C-276 page |
| Titanium Grade 2 | Titanium | R50400 | 3.7035 | — | ASTM B265: plate, sheet and strip ASTM B381 F2: forgings | ASME SB-265 / SB-381 may apply by product form and Code context. | COMMONLY ASSOCIATED Confirm commercially pure titanium grade and product condition. | Titanium Grade 2 page |
| Copper-Nickel 90/10 | Copper nickel | C70600 | CW352H / CuNi10Fe1Mn | — | ASTM B171: condenser tube plates ASTM B122: plate, sheet, strip and rolled bar | ASME SB-171 / SB-122 may apply by product form and Code context. | COMMONLY ASSOCIATED B171 is specifically a condenser tube-plate specification. | Cu-Ni 90/10 grade page |
| Copper-Nickel 70/30 | Copper nickel | C71500 | CW354H / CuNi30Mn1Fe | — | ASTM B171: condenser tube plates ASTM B122: plate, sheet, strip and rolled bar | ASME SB-171 / SB-122 may apply by product form and Code context. | COMMONLY ASSOCIATED B171 is specifically a condenser tube-plate specification. | Cu-Ni 70/30 grade page |
- 316-family EN note: EN 1.4401 and EN 1.4436 are both encountered in 316-family comparisons, but they should not be shown as identical. 1.4436 has a different, typically higher-molybdenum chemistry range. Verify the specified EN grade rather than replacing one number with the other.
- 2205 duplex note: UNS S31803 and S32205 are commonly associated within the 2205 family, but S32205 is a more tightly controlled composition range within that family. They are distinct designations and should not be treated as automatically interchangeable.
- 2507 super-duplex note: This reference intentionally leaves JIS blank. It does not assign SUS329J4L or resolve unrelated S31260 catalogue mappings without an authoritative project-specific source.
ASTM and ASME references
Why product form matters
A grade does not point to one universal ASTM number. Plate or sheet used to machine a tube sheet may be purchased to one specification, while a forged blank of the same nominal alloy is purchased to another. Bar, tube, pipe and other forms can introduce further specifications.
For that reason, the table labels the form next to each ASTM reference. A specification number without its product form, grade/type, condition and current edition is incomplete purchasing information.
ASME SA/SB specifications should be read in the applicable Code and project context. Some correspond closely to ASTM source specifications, but “ASME” and “ASTM” are not interchangeable labels on a purchase order.
Listing an ASME material specification here does not state or imply that NPRO India holds an ASME certificate, authorization or Code stamp. See the tube sheet standards and codes guide for the broader specification stack.
Procurement handoff
What to confirm before ordering a tube sheet by grade
A cross-reference can clarify terminology; the RFQ still needs the geometry, material form and project requirements that control supply.
Drawing and revisionReleased tube sheet drawing, revision and quantity.
Material identityGrade plus UNS designation where applicable.
Material specificationApplicable ASTM, ASME or other specification and edition.
Product formPlate versus forging; do not leave the form implicit.
ConstructionSolid or clad construction where relevant, with clad material identified.
Overall dimensionsDiameter, thickness and any machining allowance shown on the drawing.
Tube-hole geometryTube OD, hole diameter, pitch, pattern and drilling requirements.
Project requirementsApplicable inspection, testing and documentation requirements stated by the purchaser.
Technical basis
Technical basis and verification boundary
Designation and product-form relationships in this reference are presented as an engineering cross-reference for tube sheet material selection and procurement. Designations may vary by material family, product form, specification and applicable edition. Always verify the exact material grade, product form, dimensions, heat-treatment condition and purchaser requirements against the governing specification before approving a material substitution or issuing an order.
Standards and specifications are revised periodically. Confirm the applicable specification and current edition, exact grade/type, dimensions, heat-treatment condition and purchaser requirements before issuing an order or approving a substitution.
Continue through the NPRO reference architecture