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MATERIAL CROSS-REFERENCE · M AUSTENITIC STAINLESS (FREE-CUTTING)

AISI 303 / 1.4305: one material, every designation.

X8CrNiS18-9 is the same material your supplier may list as AISI 303 or JIS SUS303. This page maps the designations across standards and gives the ISO M-group machining starting point, brand-neutral.

EN · W.-Nr. · AISI/ASTM/UNS · JIS ISO 513 group M Free, no signup
01 · DESIGNATIONS

AISI 303 / 1.4305 across the standards

SystemDesignation
EN (EU)X8CrNiS18-9
Werkstoffnummer1.4305
AISI / ASTM / UNS (US)AISI 303 (UNS S30300)
JIS (Japan)SUS303

Compiled from the public standard designation systems (EN 10027, SAE/AISI, ASTM, UNS, JIS). Entries marked “nearest” are the closest commonly-cited counterpart, not a drop-in equivalent. Always verify against the material certificate.

02 · MACHINING

How X8CrNiS18-9 machines

The free-machining austenitic: sulphur breaks the chips 304 will not. Runs faster and cleaner than 304 at the cost of corrosion resistance and weldability on the part.

ISO groupStarting Vc (coated carbide, turning)Feed fn
M M · Stainless steel120–220 m/min · 395–720 sfm0.15–0.4 mm/rev · .006–.016 ipr

Group-level starting range from our speeds & feeds guide; convert to RPM with the speeds & feeds calculator. Condition, subgroup and operation shift the number — the material page has the detail: ISO M · Austenitic stainless (free-cutting).

Related materials: AISI 304 / 1.4301 · AISI 304L / 1.4307 · AISI 316 / 1.4401 · AISI 316L / 1.4404 · AISI 316Ti / 1.4571 · AISI 321 / 1.4541

03 · FAQ

Common questions

What is the US equivalent of X8CrNiS18-9?

X8CrNiS18-9 (Werkstoffnummer 1.4305) corresponds to AISI 303 (UNS S30300). In JIS terms the counterpart is SUS303.

Which inserts and cutting data for X8CrNiS18-9?

It is an ISO M-group material, so the starting window is 120–220 m/min · 395–720 sfm at 0.15–0.4 mm/rev · .006–.016 ipr for coated-carbide turning, adjusted for condition and operation. For a grounded, brand-neutral pick — grade, geometry and cutting data across 13 brands — ask the advisor.

Are X8CrNiS18-9 and 303 interchangeable on a drawing?

They designate the same composition under different systems, but the drawing standard governs: certificates, tolerances and delivery-condition requirements differ between standards even for equivalent chemistry. Substitute only with the certificate in hand.

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Designation solved. Now the tooling question.

Knowing the material is half the job; picking the grade and cutting data for the operation is the other half. That is what the advisor does, grounded in catalog data and honest when there is no verified match.