Stainless Steel 1.4035 +QT650
Heat-treated state
EN 1.4035
+QT650 = quenched and tempered, Rm 650–850 MPa
Choose the high-temperature-tempered condition (Rm 650–850 MPa) for medium-strength shafts and structural parts where toughness and machinability, rated 62, outweigh hardness.
Values for the +QT650 condition
Other 1.4035 tempers and conditions
1.4035 is listed in 8 conditions; see the grade overview at 1.4035.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
+ADefault Annealed | Pick the standard soft annealed stock (≤245 HB) for roughing and finishing on automatic lathes, with hardening and tempering done afterwards; machinability rates 70 but corrosion resistance is modest. | 400 | 700 | 14 | 215 HB | — |
Peeled / centreless ground bar | Use annealed bar that is peeled and centreless ground when shaft semi-finished parts or long slender turnings need high dimensional accuracy; strength stays at the annealed 700 MPa, 215 HB level. | 400 | 700 | 14 | 17 HRC | 3.1 % IACS |
+QT650This page Quenched and tempered, Rm 650–850 MPa | Choose the high-temperature-tempered condition (Rm 650–850 MPa) for medium-strength shafts and structural parts where toughness and machinability, rated 62, outweigh hardness. | 500 | 750 | 14 | 20 HRC | 3 % IACS |
Quenched and tempered, Rm 700–850 MPa | Pick this quenched and tempered delivery state (Rm 700–850 MPa) for turned valve stems and pump shafts needing both strength and wear resistance; machinability falls to 58. | 560 | 780 | 12 | 23 HRC | 3 % IACS |
Cold drawn | Choose annealed-then-cold-drawn bright bar for small turned parts needing tight tolerance and a bright surface with steadier cutting; residual stress is high and distortion risk rises. | 650 | 850 | 8 | 25 HRC | 3.1 % IACS |
Quenched and tempered, Rm 800–950 MPa | Use the high-strength quench-and-temper level (Rm 800–950 MPa, 265 HB) for fasteners and drive parts under higher loads that still require some toughness, with elongation limited to 10%. | 650 | 870 | 10 | 27 HRC | 3 % IACS |
Hardened & tempered to 43–48 HRC | Choose hardening with a temper near 300 °C to 43–48 HRC for valve plugs, wear bushings and blunt-edged tooling; wear and toughness are balanced but machinability drops to 30. | 1,200 | 1,450 | 4 | 45 HRC | — |
Hardened & low tempered to 50–54 HRC | Use quenching from 1020–1050 °C with a 180–250 °C temper to 50–54 HRC for cutlery, gauges and cutting or wear parts; this is the hardest state, with the lowest toughness and corrosion resistance. | 1,450 | 1,750 | 2 | 52 HRC | — |
What is 1.4035 +QT650?
1.4035 +QT650 is 1.4035 heat treated to +QT650 — choose the high-temperature-tempered condition (Rm 650–850 MPa) for medium-strength shafts and structural parts where toughness and machinability, rated 62, outweigh hardness. 1.4035 +QT650 has a yield strength of 500 MPa (72.5 ksi) and a tensile strength of 750 MPa (109 ksi) — stronger than 77% of stainless steel grades. Elongation at break is 14% and the elastic modulus is 215 GPa (31.2 Msi). 1.4035 +QT650 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; +QT650 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
- Easy to machine — 62/100, better than 98% of stainless steel grades
- High electrical conductivity — 3 % IACS, better than 95% of stainless steel grades
- High strength — 500 MPa (72.5 ksi), better than 77% of stainless steel grades
Limitations
- Difficult to weld — 10/100, worse than 100% of stainless steel grades
- Hard to polish — 45/100, worse than 96% of stainless steel grades
- Needs corrosion protection — 40/100, worse than 93% of stainless steel grades
- Limited formability — 14/100, worse than 92% of stainless steel grades
- Limited ductility — 14%, worse than 91% of stainless steel grades
1.4035 +QT650 properties
Typical room-temperature values for 1.4035 +QT650; 23 are specific to this condition. Other listed values are 1.4035 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
1.4035 +QT650 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).
Mechanical16
1.4035 +QT650 has a yield strength of 500 MPa (72.5 ksi) and a tensile strength of 750 MPa (109 ksi) — stronger than 77% of stainless steel grades. Elongation at break is 14% and the elastic modulus is 215 GPa (31.2 Msi).
Thermal6
1.4035 +QT650 is rated for continuous service to 400°C (752 °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
1.4035 +QT650 conducts electricity at 3 % IACS, better than 95% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is fair (40/100), worse than 93% of stainless steel grades.
Sustainability4
Producing a kilogram of 1.4035 +QT650 takes about 52 MJ of energy and emits 4.3 kg of CO₂ — less than 76% of stainless steel grades. Typical recycled content is 55%.
Manufacturability7
1.4035 +QT650's machinability is good (62/100, better than 98% of stainless steel grades); weldability not recommended (10/100); formability not recommended (14/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 1.4035 +QT650
Is 1.4035 easy to machine?
Turning behaviour is best in the annealed condition, at roughly 70 % of AISI 1212, with manganese sulfides breaking the chips; run an emulsion with extreme-pressure additives. Once hardened above 45 HRC, use CBN or ceramic inserts, or switch to grinding.
Can 1.4035 be welded?
Essentially not weldable: the combination of high carbon and sulfur promotes hot cracking and martensitic cold cracking. If a joint is unavoidable, preheat to 250–300 °C, use 309 or 410NiMo filler and temper immediately after welding; joint properties cannot be guaranteed.
Can 1.4035 be formed, bent or molded?
Cold formability is poor and limited to minor straightening and knurling. Hot work between 1100 °C and 850 °C, then cool slowly and anneal at 750–800 °C with furnace cooling.
What surface finishes work on 1.4035?
After quenching and tempering, pickle and passivate per ASTM A967 to restore the passive film. Sulfide inclusions leave pits in mirror-polished surfaces; electropolishing, PVD or electroless nickel improve both appearance and corrosion resistance.
1.4035 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 |
|---|---|---|
| C | 0.43 – 0.5 | 0.46 |
| Si | ≤ 1 | 0.4 |
| Mnhigher Mn ties up S as MnS | ≤ 1.5 | 0.8 |
| P | ≤ 0.04 | 0.03 |
| Sdeliberate free-machining addition | 0.15 – 0.35 | 0.25 |
| Cr | 12.5 – 14.5 | 13.5 |
| Mooptional / residual per EN 10088-3 | ≤ 0.6 | — |
| Fe | balance | — |
1.4035 +QT650 — frequently asked
What is 1.4035 +QT650 used for?
1.4035 +QT650 is typically used for valve components, turned cutlery parts and fasteners. In short: free-machining 420-type stainless; best-machining martensitic grade; not for welded assemblies.
What is the yield strength of 1.4035 +QT650?
1.4035 +QT650 has a typical yield strength of 500 MPa (72.5 ksi) and a tensile strength of 750 MPa (109 ksi) — stronger than 77% of stainless steel grades. Strength varies by condition: see the 8 listed tempers.
Is 1.4035 +QT650 easy to machine?
Reasonably — machinability is rated good (62/100, better than 98% of stainless steel grades). Turning behaviour is best in the annealed condition, at roughly 70 % of AISI 1212, with manganese sulfides breaking the chips; run an emulsion with extreme-pressure additives. Once hardened above 45 HRC, use CBN or ceramic inserts, or switch to grinding.
Can 1.4035 +QT650 be welded?
Not readily — weldability is rated not recommended (10/100). Essentially not weldable: the combination of high carbon and sulfur promotes hot cracking and martensitic cold cracking. If a joint is unavoidable, preheat to 250–300 °C, use 309 or 410NiMo filler and temper immediately after welding; joint properties cannot be guaranteed.
What surface finishes work on 1.4035 +QT650?
After quenching and tempering, pickle and passivate per ASTM A967 to restore the passive film. Sulfide inclusions leave pits in mirror-polished surfaces; electropolishing, PVD or electroless nickel improve both appearance and corrosion resistance.
Can 1.4035 +QT650 be formed, bent or molded?
Cold formability is poor and limited to minor straightening and knurling. Hot work between 1100 °C and 850 °C, then cool slowly and anneal at 750–800 °C with furnace cooling.
What is the maximum service temperature of 1.4035 +QT650?
1.4035 +QT650 is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- EN 10088-3 Stainless steels — Semi-finished products, bars, rods, sections — CEN (2014)
- EN 10088-1 Stainless steels — List of stainless steels — CEN (2014)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels — ASM International (1990)
- Free-machining martensitic stainless bar (X46CrS13 / 420F) data sheets — European long-product mills (2023)
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.