Stainless Steel 1.4031 +QT800
Heat-treated state
EN 1.4031
+QT800 = quenched and tempered to 800–950 MPa tensile
Choose for shafts, pins, valve parts and fittings that need moderate strength with usable ductility rather than maximum hardness (high tempering temperature).
Values for the +QT800 condition
Other 1.4031 tempers and conditions
1.4031 is listed in 6 conditions; see the grade overview at 1.4031.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
+ADefault Annealed | Standard supply condition for bar, strip and blanks that will be machined/blanked and hardened afterwards. | 450 | 760 | 16 | 220 HB | — |
+QT800This page Quenched and tempered to 800–950 MPa tensile | Choose for shafts, pins, valve parts and fittings that need moderate strength with usable ductility rather than maximum hardness (high tempering temperature). | 660 | 870 | 14 | 27 HRC | — |
Cold drawn | Pick for close-tolerance bright bar or hard strip where extra straightness and surface finish are needed before hardening. | 700 | 900 | 10 | 27 HRC | 3.1 % IACS |
Quenched and tempered to 900–1050 MPa tensile | Mill-supplied higher-strength quenched-and-tempered bar where a bit more yield strength is required and ductility can drop. | 750 | 960 | 12 | 31 HRC | — |
Hardened and tempered 350–450 °C | Used when slightly higher toughness than the cutlery temper is needed; avoid if maximum corrosion resistance matters (secondary carbide precipitation). | 1,350 | 1,600 | 5 | 49 HRC | — |
Hardened ~1030 °C, oil/air quenched, tempered 150–200 °C | The cutlery/instrument condition: maximum hardness, wear resistance and edge retention, at the cost of very low impact toughness. | 1,550 | 1,900 | 2 | 55 HRC | — |
What is 1.4031 +QT800?
1.4031 +QT800 is 1.4031 heat treated to +QT800 — choose for shafts, pins, valve parts and fittings that need moderate strength with usable ductility rather than maximum hardness (high tempering temperature). 1.4031 +QT800 has a yield strength of 660 MPa (95.7 ksi) and a tensile strength of 870 MPa (126 ksi) — stronger than 91% of stainless steel grades. Elongation at break is 14% and the elastic modulus is 215 GPa (31.2 Msi). 1.4031 +QT800 has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 83% of stainless steel grades. It melts at 1,420°C (2,588 °F). +A is the default condition FabDigit quotes; +QT800 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
- High electrical conductivity — 3.1 % IACS, better than 99% of stainless steel grades
- Polishes to a fine finish — 85/100, better than 97% of stainless steel grades
- High strength — 660 MPa (95.7 ksi), better than 91% of stainless steel grades
- Low embodied carbon — 3.8 kg CO₂/kg, better than 77% of stainless steel grades
Limitations
- Difficult to weld — 15/100, worse than 98% of stainless steel grades
- Limited ductility — 14%, worse than 91% of stainless steel grades
- Limited formability — 15/100, worse than 91% of stainless steel grades
- Needs corrosion protection — 45/100, worse than 85% of stainless steel grades
1.4031 +QT800 properties
Typical room-temperature values for 1.4031 +QT800; 19 are specific to this condition. Other listed values are 1.4031 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
1.4031 +QT800 has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 83% of stainless steel grades. It melts at 1,420°C (2,588 °F).
Mechanical15
1.4031 +QT800 has a yield strength of 660 MPa (95.7 ksi) and a tensile strength of 870 MPa (126 ksi) — stronger than 91% of stainless steel grades. Elongation at break is 14% and the elastic modulus is 215 GPa (31.2 Msi).
Thermal6
1.4031 +QT800 is rated for continuous service to 500°C (932 °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
1.4031 +QT800 conducts electricity at 3.1 % IACS, better than 99% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is fair (45/100), worse than 85% of stainless steel grades.
Sustainability4
Producing a kilogram of 1.4031 +QT800 takes about 45 MJ of energy and emits 3.8 kg of CO₂ — less than 91% of stainless steel grades. Typical recycled content is 60%.
Manufacturability8
1.4031 +QT800's machinability is fair (35/100, better than 51% of stainless steel grades); weldability poor (15/100); formability poor (15/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 1.4031 +QT800
Is 1.4031 easy to machine?
Machine in the annealed condition with sharp, rigid carbide tooling, moderate speed and heavy coolant; the alloy work-hardens and is nearly ungrindable-only above ~45 HRC.
Can 1.4031 be welded?
Poor weldability due to ~0.4 %C — preheat 250–350 °C, use matching or austenitic (309/316) filler and temper immediately after welding, otherwise cracking is likely.
Can 1.4031 be formed, bent or molded?
Cold form only in the soft annealed state and with generous bend radii; hot work 1100→850 °C followed by slow furnace cooling, harden from 1000–1050 °C in oil/air and temper below 250 °C.
What surface finishes work on 1.4031?
Takes a mirror polish; passivate in nitric or citric acid after machining and grinding, and consider hard-chrome or PVD coatings for extra wear/corrosion protection — no anodizing.
1.4031 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 10088-1 X39Cr13 | 0.36 – 0.42 | 0.39 |
| Si | ≤ 1 | 0.4 |
| Mn | ≤ 1 | 0.5 |
| P | ≤ 0.04 | — |
| S≤0.015 for some cutlery strip qualities | ≤ 0.03 | — |
| Cr | 12.5 – 14.5 | 13.5 |
| Niresidual, mill practice limit | ≤ 0.5 | — |
| Fe | balance | — |
1.4031 +QT800 — frequently asked
What is 1.4031 +QT800 used for?
1.4031 +QT800 is typically used for knives, scissors, surgical instruments and dental tools. In short: 54–56 HRC blade steel; hardest 13% Cr grade here; not for welded assemblies.
What is the yield strength of 1.4031 +QT800?
1.4031 +QT800 has a typical yield strength of 660 MPa (95.7 ksi) and a tensile strength of 870 MPa (126 ksi) — stronger than 91% of stainless steel grades. Strength varies by condition: see the 6 listed tempers.
Is 1.4031 +QT800 easy to machine?
Not especially — machinability is rated fair (35/100, better than 51% of stainless steel grades). Machine in the annealed condition with sharp, rigid carbide tooling, moderate speed and heavy coolant; the alloy work-hardens and is nearly ungrindable-only above ~45 HRC.
Can 1.4031 +QT800 be welded?
Not readily — weldability is rated poor (15/100). Poor weldability due to ~0.4 %C — preheat 250–350 °C, use matching or austenitic (309/316) filler and temper immediately after welding, otherwise cracking is likely.
What surface finishes work on 1.4031 +QT800?
Takes a mirror polish; passivate in nitric or citric acid after machining and grinding, and consider hard-chrome or PVD coatings for extra wear/corrosion protection — no anodizing.
Can 1.4031 +QT800 be formed, bent or molded?
Cold form only in the soft annealed state and with generous bend radii; hot work 1100→850 °C followed by slow furnace cooling, harden from 1000–1050 °C in oil/air and temper below 250 °C.
What is the maximum service temperature of 1.4031 +QT800?
1.4031 +QT800 is rated for continuous use to about 500°C (932 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- EN 10088-1 Stainless steels — List of stainless steels — CEN (2014)
- EN 10088-3 Technical delivery conditions for semi-finished products, bars, rods, wire and sections — CEN (2014)
- GB/T 1220 (4Cr13) — SAC (2007)
- JIS G 4303 (SUS420J2) — JSA (2021)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- Martensitic stainless steel X39Cr13 / 1.4031 data sheet — European long-products mill (typical) (2022)
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.