Stainless Steel 1.4006 +QT550
Heat-treated state
EN 1.4006 · UNS S41000 · AISI/SAE 410 · JIS SUS410 · GB 06Cr13, 1Cr13
+QT550 = quenched and tempered to Rm 550–750 MPa
High-temperature tempered condition for shafts and fittings needing good toughness with moderate strength.
Values for the +QT550 condition
Other 1.4006 tempers and conditions
1.4006 is listed in 5 conditions; see the grade overview at 1.4006.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
+ADefault Annealed | Stock condition for machining, cold forming and subsequent hardening by the user. | 300 | 520 | 24 | 155 HB | — |
+QT550This page Quenched and tempered to Rm 550–750 MPa | High-temperature tempered condition for shafts and fittings needing good toughness with moderate strength. | 420 | 620 | 19 | 190 HB | — |
Quenched and tempered to Rm 650–850 MPa | Standard structural strength condition for valve stems, pump shafts, bolts and turbine parts. | 520 | 730 | 17 | 21 HRC | — |
Cold drawn | Bright, close-tolerance bar for machined parts where extra strength and good surface finish are wanted without heat treatment. | 550 | 700 | 14 | 220 HB | — |
Hardened | Pick for wear parts, cutlery-type blades and seats where hardness matters more than toughness or corrosion resistance. | 1,050 | 1,350 | 12 | 42 HRC | — |
What is 1.4006 +QT550?
1.4006 +QT550 is 1.4006 heat treated to +QT550 — high-temperature tempered condition for shafts and fittings needing good toughness with moderate strength. 1.4006 +QT550 has a yield strength of 420 MPa (60.9 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 64% of stainless steel grades. Elongation at break is 19% and the elastic modulus is 215 GPa (31.2 Msi). 1.4006 +QT550 has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 83% of stainless steel grades. It melts at 1,480°C (2,696 °F). +A is the default condition FabDigit quotes; +QT550 is available on request or by drawing note.
Advantages
- Conducts heat well — 30 W/m·K (17.3 BTU/hr·ft·°F), better than 99% of stainless steel grades
- Low embodied carbon — 3.2 kg CO₂/kg, better than 95% of stainless steel grades
- High electrical conductivity — 2.9 % IACS, better than 87% of stainless steel grades
Limitations
- Needs corrosion protection — 39/100, worse than 94% of stainless steel grades
- Difficult to weld — 35/100, worse than 86% of stainless steel grades
- Limited ductility — 19%, worse than 81% of stainless steel grades
- Limited formability — 25/100, worse than 78% of stainless steel grades
- Low fracture toughness — 85 MPa·√m (77.4 ksi·√in), worse than 77% of stainless steel grades
1.4006 +QT550 properties
Typical room-temperature values for 1.4006 +QT550; 18 are specific to this condition. Other listed values are 1.4006 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
1.4006 +QT550 has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 83% of stainless steel grades. It melts at 1,480°C (2,696 °F).
Mechanical16
1.4006 +QT550 has a yield strength of 420 MPa (60.9 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 64% of stainless steel grades. Elongation at break is 19% and the elastic modulus is 215 GPa (31.2 Msi).
Thermal6
1.4006 +QT550 is rated for continuous service to 600°C (1,112 °F). It conducts heat at 30 W/m·K (17.3 BTU/hr·ft·°F), better than 99% of stainless steel grades. Thermal expansion is 10.5 µm/m·K (5.83 µin/in·°F).
Electrical3
1.4006 +QT550 conducts electricity at 2.9 % IACS, better than 87% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is fair (39/100), worse than 94% of stainless steel grades.
Sustainability4
Producing a kilogram of 1.4006 +QT550 takes about 45 MJ of energy and emits 3.2 kg of CO₂ — less than 91% of stainless steel grades. Typical recycled content is 60%.
Manufacturability7
1.4006 +QT550's machinability is fair (42/100, better than 79% of stainless steel grades); weldability fair (35/100); formability poor (25/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 1.4006 +QT550
Is 1.4006 easy to machine?
Machine in the annealed or ≤26 HRC condition with sharp, rigid tooling, positive rake carbide and generous coolant; expect ~50–55 % of 1212 free-cutting steel and gummy chips at low hardness.
Can 1.4006 be welded?
Weldable with preheat 200–300 °C and immediate post-weld temper at 700–750 °C using 410 or austenitic 309/308L filler; unpreheated welds crack from hard, brittle martensite in the HAZ.
Can 1.4006 be formed, bent or molded?
Cold form only in the annealed state with generous bend radii (≥2t) and stress-relieve afterwards; hot work 1100–1200 °C and cool slowly to avoid quench cracking.
What surface finishes work on 1.4006?
Passivate (ASTM A967 nitric or citric) after machining, or electropolish for best corrosion behaviour; takes a good mechanical polish and accepts hard chrome, nitriding or PVD coatings — no anodising.
1.4006 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| CEN 10088-3 X12Cr13 | 0.08 – 0.15 | 0.12 |
| Si | ≤ 1 | 0.4 |
| Mn | ≤ 1.5 | 0.6 |
| P | ≤ 0.04 | 0.03 |
| S0.15–0.35 S in free-machining variant 1.4005 / 416 | ≤ 0.03 | 0.02 |
| Cr | 11.5 – 13.5 | 12.5 |
| Ni | ≤ 0.75 | 0.3 |
| Fe | balance | — |
1.4006 +QT550 — frequently asked
What is 1.4006 +QT550 used for?
1.4006 +QT550 is typically used for turbine blades, cutlery, valve parts, fasteners and pump shafts. In short: baseline 13% Cr martensitic; most weldable martensitic grade; 650 °C service limit.
What is the yield strength of 1.4006 +QT550?
1.4006 +QT550 has a typical yield strength of 420 MPa (60.9 ksi) and a tensile strength of 620 MPa (89.9 ksi) — stronger than 64% of stainless steel grades. Strength varies by condition: see the 5 listed tempers.
Is 1.4006 +QT550 easy to machine?
Not especially — machinability is rated fair (42/100, better than 79% of stainless steel grades). Machine in the annealed or ≤26 HRC condition with sharp, rigid tooling, positive rake carbide and generous coolant; expect ~50–55 % of 1212 free-cutting steel and gummy chips at low hardness.
Can 1.4006 +QT550 be welded?
With care — weldability is rated fair (35/100). Weldable with preheat 200–300 °C and immediate post-weld temper at 700–750 °C using 410 or austenitic 309/308L filler; unpreheated welds crack from hard, brittle martensite in the HAZ.
What surface finishes work on 1.4006 +QT550?
Passivate (ASTM A967 nitric or citric) after machining, or electropolish for best corrosion behaviour; takes a good mechanical polish and accepts hard chrome, nitriding or PVD coatings — no anodising.
Can 1.4006 +QT550 be formed, bent or molded?
Cold form only in the annealed state with generous bend radii (≥2t) and stress-relieve afterwards; hot work 1100–1200 °C and cool slowly to avoid quench cracking.
What is the maximum service temperature of 1.4006 +QT550?
1.4006 +QT550 is rated for continuous use to about 600°C (1,112 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 1.4006 +A and 1.4006-H?
+A is the default condition — stock condition for machining, cold forming and subsequent hardening by the user. H: pick for wear parts, cutlery-type blades and seats where hardness matters more than toughness or corrosion resistance. Yield strength is 300 MPa in +A versus 1,050 MPa in H.
Sources
- EN 10088-3 Stainless steels — semi-finished products, bars, rods — CEN (2014)
- ASTM A276/A276M Stainless Steel Bars and Shapes — ASTM (2023)
- GB/T 1220 — SAC (2007)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels — ASM International (1990)
- Martensitic stainless steel 410/1.4006 datasheet — Outokumpu / Sandvik (2021)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.