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MATERIAL CROSS-REFERENCE · M MARTENSITIC STAINLESS

AISI 420 / 1.4021: one material, every designation.

X20Cr13 is the same material your supplier may list as AISI 420 or JIS SUS420J1. 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 420 / 1.4021 across the standards

SystemDesignation
EN (EU)X20Cr13
Werkstoffnummer1.4021
AISI / ASTM / UNS (US)AISI 420 (UNS S42000, nearest)
JIS (Japan)SUS420J1

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.

NEAREST MATCH, NOT A TWIN

At least one designation on this page is a nearest commonly-cited counterpart rather than a same-composition equivalent (structural and cast grades are specified by properties, not chemistry). Confirm suitability against the material certificate and the drawing requirement, not this table alone.

02 · MACHINING

How X20Cr13 machines

AISI 420 spans the X20Cr13-X46Cr13 family, so the EN match is nearest-by-carbon. Machine annealed where possible; hardened cutlery-temper 420 eats edges.

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 · Martensitic stainless.

Related materials: AISI 410 / 1.4006 · AISI 430 / 1.4016 · AISI 431 / 1.4057

03 · FAQ

Common questions

What is the US equivalent of X20Cr13?

X20Cr13 (Werkstoffnummer 1.4021) corresponds to AISI 420 (UNS S42000, nearest) as the nearest commonly-cited counterpart — check the certificate before substituting. In JIS terms the counterpart is SUS420J1.

Which inserts and cutting data for X20Cr13?

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 X20Cr13 and 420 interchangeable on a drawing?

Not automatically: this pairing is nearest-by-properties, and structural or cast grades are specified by mechanical requirements. The drawing standard and the material certificate decide, not the cross-reference table.

NEXT

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.