EN 1.4006 Martensitic Stainless Steel: Properties, Equivalents and Applications

What Is EN 1.4006 Stainless Steel?

EN 1.4006 is a martensitic stainless steel containing roughly 12-14% chromium and a maximum carbon level of 0.15%. Because it carries almost no nickel, the grade transforms fully to martensite when it is cooled from the austenitising temperature, and it therefore responds strongly to hardening and tempering. That behaviour is why the steel is selected wherever hardness, strength and wear resistance matter more than maximum corrosion resistance.

The grade is magnetic in every heat-treatment condition, and its corrosion performance sits in the moderate range: clearly better than unalloyed or low-alloy steel, but below the austenitic 18/8 family such as Grade 304 (EN 1.4301). In EN 10088-2 and EN 10088-3 the material is designated X12Cr13. In ASTM/AISI practice it is Type 410 with the UNS number S41000, the nearest Chinese designation is 1Cr13, and the nearest Japanese designation is SUS410.

Common product forms include hot rolled and cold drawn round bar, square bar, hexagon bar, plate, sheet, strip, seamless tube, wire rod, forgings and finished machined parts. Bar is normally supplied annealed, hardened and tempered, or peeled and polished, with tolerances and surface quality to the applicable product standard.

Chemical Composition and Mechanical Properties

Table 1 gives the normal specification ranges for EN 1.4006 / AISI 410. Heat-specific results are reported on the mill test certificate for every cast.

Element	Typical content (%)
Carbon (C)	0.08 - 0.15
Silicon (Si)	≤ 1.00
Manganese (Mn)	≤ 1.00
Phosphorus (P)	≤ 0.040
Sulfur (S)	≤ 0.030
Chromium (Cr)	11.50 - 13.50
Nickel (Ni)	≤ 0.75
Iron (Fe)	Balance

Table 2 compares typical mechanical properties in the annealed condition and after hardening and tempering. The spread in the hardened values reflects the tempering temperature: low-temperature tempering gives maximum strength and hardness, while high-temperature tempering trades some strength for ductility and impact toughness.

Property	Annealed	Hardened and tempered
Tensile strength	approx. 480 - 550 MPa	700 - 950 MPa
Yield strength (0.2% offset)	approx. 275 MPa	550 - 750 MPa
Elongation in 50 mm	approx. 20%	approx. 15%
Hardness	up to 250 HB	up to 500 HB depending on temper
Modulus of elasticity	approx. 200 GPa	approx. 200 GPa
Magnetic response	Magnetic	Magnetic

Grade Equivalents and Comparison with Related Grades

Standard system	Equivalent designation
AISI / ASTM	410
UNS	S41000
DIN / EN (EN 10088)	X12Cr13, material number 1.4006
JIS	SUS410
GB (China)	1Cr13

EN 1.4006 is equivalent to AISI 410, so the two are interchangeable in many global applications that call for the same strength and corrosion behaviour. Two comparisons are asked about most often.

Property	1.4003 (ferritic)	1.4006 (martensitic)
Microstructure	Ferritic	Martensitic
Hardening by heat treatment	Not hardenable	Hardenable
Tensile strength	Moderate, around 500 MPa	High, above 700 MPa after hardening
Corrosion resistance	Good in dry atmospheres	Moderate
Typical use	Structural parts and frames	Shafts, pumps, valves

Property	1.4401 / AISI 316	1.4006 / AISI 410
Chromium (Cr)	16.0 - 18.0%	11.5 - 13.5%
Nickel (Ni)	10.0 - 14.0%	None specified
Molybdenum (Mo)	2.0 - 3.0%	None specified
Corrosion resistance	Excellent, including in chloride media	Moderate
Hardenability	Non-hardenable by heat treatment	Hardenable
Magnetic response	Non-magnetic in the annealed state	Magnetic
Typical use	Marine and chemical plant	Turbine blades, pumps, valve trim

1.4003 is the more formable and weldable choice, while 1.4006 is the better choice for high-strength and wear-resistant components. 1.4401 (AISI 316) offers far higher corrosion resistance, especially in aggressive or chloride-bearing environments, whereas 1.4006 is preferred where wear resistance and mechanical strength after heat treatment are the deciding factors.

Heat Treatment, Welding and Machining

Annealing: heat to approximately 750-850 °C, hold until uniform, then cool slowly to soften the structure and relieve stress.

Hardening: austenitise at approximately 950-1000 °C, then quench in oil or air to develop a fully martensitic structure.

Tempering: temper immediately after quenching, either at 200-400 °C for maximum strength or at 600-750 °C for a better balance of strength and toughness.

Welding: the grade can be welded, but its martensitic structure and relatively high carbon content make it prone to cracking. Preheat to 150-300 °C, keep heat input controlled, use matching or low-hydrogen filler metal, and apply post-weld heat treatment to restore properties and reduce hardness and brittleness.

Machining: always machine in the annealed condition where possible; hardened and tempered material requires carbide tooling, rigid set-ups and reduced cutting speeds.

Typical Applications and Selection Guidance

Pump shafts, impellers, valve stems and valve trim

Steam turbine blades and other moderately stressed turbine components

Screws, bolts, nuts, studs and fasteners that need strength plus light corrosion protection

Cutlery, scissors, hand tools and other hardened wear-resistant parts

Bushings, spindles, moulds, dies and general engineering hardware

Petrochemical and power plant components exposed to mildly corrosive media

Selection guidance is straightforward: choose 1.4006 when the requirement is hardness, strength or wear resistance in a mildly corrosive environment, and move to a molybdenum-bearing austenitic grade such as 1.4401 or a duplex grade when chlorides, acids or marine exposure dominate. Confirm the required delivery condition, hardness range and non-destructive testing before ordering.

Frequently Asked Questions

Q: Is EN 1.4006 the same as AISI 410 stainless steel?
Yes. EN 1.4006, X12Cr13 and AISI 410 (UNS S41000) describe the same 12% chromium martensitic stainless steel, so they can normally be substituted for one another once the product form and test requirements are agreed.

Q: Is 1.4006 magnetic?
Yes. Because the structure is martensitic with virtually no nickel, 1.4006 is strongly magnetic in the annealed, hardened and tempered conditions alike.

Q: Can 1.4006 be hardened by heat treatment?
Yes. The steel is austenitised at about 950-1000 °C and quenched to form martensite, then tempered to the required strength and hardness level.

Q: What is the maximum hardness of 1.4006?
Hardness depends on the tempering temperature. In the annealed state it is up to about 250 HB, while hardening followed by low-temperature tempering can raise it to approximately 500 HB.

Q: How does 1.4006 compare with 1.4003?
1.4003 is a ferritic grade that cannot be hardened and has better forming and welding characteristics. 1.4006 is martensitic, hardenable and much stronger, which suits shafts, pumps and valves rather than frames and structural parts.

Q: How does 1.4006 compare with 316 stainless steel?
Type 316 (EN 1.4401) contains chromium, nickel and molybdenum and delivers far higher corrosion resistance, especially in chloride environments, but it cannot be hardened by heat treatment. 1.4006 is the better choice when strength and wear resistance are the priority.