1.4028 Stainless Steel Equivalent Grades, Composition and Properties

What Is EN 1.4028 Stainless Steel?

EN 1.4028 is the numeric designation of X30Cr13, a high-carbon martensitic stainless steel defined in the EN 10088 series. Around 13% chromium combined with roughly 0.30% carbon gives the grade a strong response to quenching and tempering, so finished parts can combine high surface hardness with useful resistance to fresh water, steam, mildly acidic media and normal atmospheric exposure.

The grade is normally supplied and used in the hardened and tempered condition. In the soft annealed state it machines and grinds easily, which makes it a practical choice for components that are formed first and heat treated afterwards. Anyone searching for a 1.4028 stainless steel equivalent therefore has to compare the carbon range as well as the designation, because the hardness that can be reached depends directly on carbon content.

1.4028 Stainless Steel Equivalent Grades

Standard	Equivalent grade
EN / DIN (Europe)	1.4028 / X30Cr13
AISI / ASTM	420 modified, at the higher-carbon end of the AISI 420 range
UNS	S42000
JIS (Japan)	SUS 420J2
GB (China)	3Cr13
BS (United Kingdom)	420S45

AISI 420 is a family designation that begins at about 0.15% carbon, whereas X30Cr13 sits at the upper end of that family. A quotation written simply as 420 therefore does not guarantee the hardness response of 1.4028. For bar, rod and wire products the most precise route is to order against EN 10088-3 with the X30Cr13 analysis, or against GB/T 1220 with the 3Cr13 analysis, and to state the required delivery condition at the same time.

Chemical Composition of X30Cr13 and 3Cr13

Element	EN 1.4028 (X30Cr13)	AISI 420	3Cr13 (GB)
C	0.26 - 0.35%	0.15% min	0.26 - 0.35%
Cr	12.5 - 14.5%	12.0 - 14.0%	12.0 - 14.0%
Mn	1.00% max	1.00% max	1.00% max
Si	1.00% max	1.00% max	1.00% max
P	0.040% max	0.040% max	0.040% max
S	0.030% max	0.030% max	0.030% max

Density is about 7.7 g/cm3 and the annealed structure is ferritic with globular carbides, transforming to a fully martensitic structure after hardening. Free-machining members of the 420 family raise the sulphur content to improve chip breaking, but those are separate designations with lower corrosion resistance and should not be used as a drop-in replacement for X30Cr13.

Mechanical Properties and Heat Treatment

Typical values for the quenched and tempered condition are shown below.

Property	1.4028 in QT condition
Tensile strength Rm	800 - 1,000 MPa
Yield strength Rp0.2	600 MPa min
Hardness	230 - 280 HBW
Elongation A5	about 10 - 15%

The usual heat treatment route has three steps:

Soft annealing at about 800 - 850 C followed by slow cooling, which brings the hardness down to roughly 200 HBW so the part can be machined.

Hardening by austenitising at about 980 - 1,050 C and then quenching in oil or air. The achievable hardness depends on carbon content, austenitising temperature and section thickness.

Tempering after quenching. A low temperature range of about 200 - 400 C preserves the highest hardness at the cost of toughness, while 600 - 700 C sacrifices some hardness in exchange for much better ductility and impact strength.

Because 1.4028 is an air-hardening steel, heavy sections may harden only partially when air cooled, so the quench medium must be matched to the ruling section. Tempering between roughly 400 and 600 C should be avoided where maximum corrosion resistance is required, since carbide precipitation ties up chromium in the matrix.

Applications and Selection Notes

Industrial and cutlery blades where edge retention and wear resistance are the deciding factors.

Pump shafts, valve stems, spindles and wear plates requiring strength plus moderate corrosion resistance.

Fasteners, bushings, gauges, nozzles and instrument parts produced in the hardened and polished condition.

Food processing and petrochemical hardware exposed to fresh water, steam or mildly acidic products rather than chloride-rich media.

Where chlorides, strong acids or continuous wet service are involved, a higher-alloyed austenitic or duplex stainless steel is the better engineering choice. Where 1.4028 is selected, the acceptance standard, hardness range and delivery condition belong on the purchase order, and a mill test certificate to EN 10204 3.1 should accompany the material so that the heat treatment result can be traced back to the cast.

FAQ

Q: Is 1.4028 the same as AISI 420?
They belong to the same martensitic family, but 1.4028 has a carbon range of 0.26 - 0.35%, well above the 0.15% minimum of generic AISI 420, so it hardens to a higher working hardness.

Q: Can 1.4028 stainless steel be hardened by heat treatment?
Yes. It is hardened by austenitising at about 980 - 1,050 C followed by oil or air quenching, and the hardness is then adjusted by tempering.

Q: What is the Chinese equivalent of 1.4028?
The closest Chinese grade is 3Cr13 under GB/T 1220, which shares the same carbon and chromium ranges.

Q: Is 1.4028 stainless steel magnetic?
Yes. Its martensitic structure is ferromagnetic in both the annealed and the hardened condition.

Q: How does 1.4028 compare with 316 stainless steel for corrosion?
316 is clearly superior in chloride and acid service because of its molybdenum addition, while 1.4028 is chosen when hardness and wear resistance matter more than corrosion resistance.