Home / Guides / Materials

JIS to AISI Stainless Equivalents: A Reference Table for Part Drawings

Materials / 18 Aug 2026

If your drawing says SUS316L and the shop quoting it buys bar from a European stockist, somebody has to make the translation. Done casually it works most of the time. Done casually on the one job where the certificate is inspected, it costs a rejected lot.

This is the cross reference, followed by the places where “equivalent” is doing more work than it should.

The table

JIS	AISI / ASTM	EN number	EN name	UNS	Family
SUS301	301	1.4310	X10CrNi18-8	S30100	Austenitic
SUS303	303	1.4305	X8CrNiS18-9	S30300	Austenitic
SUS304	304	1.4301	X5CrNi18-10	S30400	Austenitic
SUS304L	304L	1.4307	X2CrNi18-9	S30403	Austenitic
SUS305	305	1.4303	X4CrNi18-12	S30500	Austenitic
SUS309S	309S	1.4833	X12CrNi23-13	S30908	Austenitic
SUS310S	310S	1.4845	X8CrNi25-21	S31008	Austenitic
SUS316	316	1.4401	X5CrNiMo17-12-2	S31600	Austenitic
SUS316L	316L	1.4404	X2CrNiMo17-12-2	S31603	Austenitic
SUS321	321	1.4541	X6CrNiTi18-10	S32100	Austenitic
SUS347	347	1.4550	X6CrNiNb18-10	S34700	Austenitic
SUS405	405	1.4002	X6CrAl13	S40500	Ferritic
SUS410	410	1.4006	X12Cr13	S41000	Martensitic
SUS420J1	420	1.4021	X20Cr13	S42000	Martensitic
SUS420J2	420	1.4028	X30Cr13	-	Martensitic
SUS430	430	1.4016	X6Cr17	S43000	Ferritic
SUS440C	440C	1.4125	X105CrMo17	S44004	Martensitic
SUS630	630 / 17-4 PH	1.4542	X5CrNiCuNb16-4	S17400	Precipitation hardening
SUS631	631 / 17-7 PH	1.4568	X7CrNiAl17-7	S17700	Precipitation hardening
SUS329J1	-	1.4460	X3CrNiMoN27-5-2	S32900	Duplex

Where equivalent stops meaning identical

Four cases are worth knowing before you rely on the table.

SUS420J1 and SUS420J2 both map to AISI 420. They are not the same material. J1 carries roughly 0.16 to 0.25 % carbon, J2 carries roughly 0.26 to 0.40 %. That is the difference between about 50 HRC and about 55 HRC after hardening, and the difference between two very different machining sequences. AISI 420 covers both ranges in one designation, which is why the JIS split exists. If your drawing says SUS420J2, do not let it become “420” in the quote without checking which end of the carbon range the shop will buy.

Low carbon variants. SUS304L and SUS316L cap carbon at 0.030 %. Some mills supply dual certified 304/304L material that meets both. That is usually good news, but if the drawing calls for 304 specifically because it needs the higher strength that comes with the higher carbon, dual certified material is not automatically the same thing.

Ferritic mapping is loose. SUS430 and EN 1.4016 are close. SUS405 and 1.4002 are close. Beyond that the ferritic families diverge between standards more than the austenitics do, and the table should be treated as a starting point rather than an answer.

Duplex has no clean JIS to AISI bridge. AISI never developed a duplex numbering scheme, so duplex grades are normally called out by UNS or EN number. If a JIS drawing calls SUS329J1, quote it against UNS S32900 or EN 1.4460 and state which.

The certificate is the real trap

The grades line up. The paperwork does not.

A European stockist certifies stainless bar against EN 10088 and issues a certificate to EN 10204, usually type 3.1, signed by the mill’s own inspection department. A Japanese mill issues a mill sheet against JIS G 4303. Both describe material that satisfies your design. Neither is the other.

So on the drawing, be explicit about three things:

The grade. SUS316L.
What you will accept as equivalent. EN 1.4404 or ASTM A276 Type 316L, or neither.
The certificate. EN 10204 3.1, a JIS mill sheet, or traceability down to the heat lot.

A line such as SUS316L (EN 1.4404 acceptable), mill certificate to EN 10204 3.1 required removes every ambiguity, costs you nothing, and stops the quote coming back with a caveat.

Which JIS product standard applies

The grade designation is the same regardless of form. The product standard changes:

Standard	Covers
JIS G 4303	Stainless steel bars
JIS G 4304	Hot rolled stainless plate, sheet and strip
JIS G 4305	Cold rolled stainless plate, sheet and strip
JIS G 4308	Stainless steel wire rod
JIS G 4309	Stainless steel wire
JIS G 3459	Stainless steel pipes
JIS G 4315	Stainless steel wire for cold heading

If the note in your title block says only “SUS304”, a shop buying plate and a shop buying bar are both compliant. If the part must come from bar, say so.

Using the table when you source outside Japan

Practical phrasing by region, for an RFQ or a stockist enquiry:

Europe: give the EN number first, the JIS grade second. 1.4404 (SUS316L). EN numbers are what the stockist’s system runs on.
North America: give the AISI type and the ASTM product spec. 316L per ASTM A276.
Rest of Asia: JIS designations are widely understood and often the primary system. SUS316L on its own is usually enough.
Anywhere: add the UNS code as a tie breaker. It is unambiguous and internationally recognised.

For what each grade costs you under a tool once the designation is settled, see the machinability and cost comparison, and for the rest of what belongs on a JIS drawing, the SUS304 machining guide.

Working from a drawing right now? Get a quote. An engineer reads the grade and the certificate line and prices the part within 24 business hours.

Questions

Is SUS304 exactly the same as AISI 304?

The composition ranges overlap almost completely, so for design purposes they are the same material. The certificates are not the same document, and an inspector told to expect a JIS G 4303 certificate will not accept one written against EN 10088.

What does the SUS prefix mean?

Steel Use Stainless. It is the JIS designation prefix, followed by the number that in most cases matches the AISI type. SUS304 is AISI 304, SUS316 is AISI 316. The suffix letters, J1 and J2, are JIS specific sub grades with no AISI equivalent.

Which JIS standard covers stainless bar?

JIS G 4303 for bars, JIS G 4304 for hot rolled plate, sheet and strip, JIS G 4305 for cold rolled plate, sheet and strip. The grade designation is the same across all of them, only the product form changes.

What should I write on the drawing if the shop is outside Japan?

Write the JIS grade, then add the equivalent you will accept and the certificate standard you require. For example: SUS316L, EN 1.4404 acceptable, mill certificate to EN 10204 3.1.

Have a drawing for a stainless part?

Send it and an engineer reads the title block, quotes it within 24 business hours, and if you order we place, manage, inspect and ship the parts on one PO and one invoice.

Get a quote