Stainless Steel S42035-QT650
Heat-treated state
UNS S42035
QT650 = hardened, tempered 650 °C
Lowest-hardness Q&T condition, chosen when a hardness cap (e.g. ≤28 HRC) and maximum ductility are specified.
Values for the QT650 condition
Other S42035 tempers and conditions
S42035 is listed in 8 conditions; see the grade overview at S42035.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ADefault Solution annealed | Standard stock condition for machining and forming before hardening. | 380 | 690 | 22 | 215 HB | — |
Hot rolled | Black bar or forging as supplied from the mill; must be annealed before serious machining. | 600 | 900 | 14 | 29 HRC | 3 % IACS |
Cold drawn | Bright cold-drawn bar for close tolerance turned parts and shafts that stay unhardened. | 650 | 830 | 13 | 25 HRC | — |
QT650This page Hardened, tempered 650 °C | Lowest-hardness Q&T condition, chosen when a hardness cap (e.g. ≤28 HRC) and maximum ductility are specified. | 690 | 860 | 19 | 26 HRC | — |
Hardened, tempered 595 °C | Toughness-oriented condition for valve stems, pump shafts and fasteners where impact matters more than hardness. | 830 | 1,030 | 16 | 33 HRC | — |
Hardened, tempered 315 °C | Slightly tougher than the 205 °C temper while keeping high wear resistance. | 1,330 | 1,570 | 10 | 46 HRC | — |
Hardened ~1010 °C, oil/air quenched, tempered 205 °C | Maximum hardness and wear resistance for valve trim, seats and cutting edges. | 1,450 | 1,720 | 8 | 50 HRC | — |
Hardened and stress relieved | Peak hardness for thin wear parts and blades where dimensional stability, not toughness, governs. | 1,500 | 1,850 | 4 | 53 HRC | — |
What is S42035-QT650?
S42035-QT650 is S42035 heat treated to QT650 — lowest-hardness Q&T condition, chosen when a hardness cap (e.g. ≤28 HRC) and maximum ductility are specified. S42035-QT650 has a yield strength of 690 MPa (100 ksi) and a tensile strength of 860 MPa (125 ksi) — stronger than 92% of stainless steel grades. Elongation at break is 19% and the elastic modulus is 200 GPa (29 Msi). S42035-QT650 has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 83% of stainless steel grades. It melts at 1,454°C (2,649 °F). A is the default condition FabDigit quotes; QT650 is available on request or by drawing note.
Advantages
- High electrical conductivity — 3.1 % IACS, better than 99% of stainless steel grades
- High strength — 690 MPa (100 ksi), better than 92% of stainless steel grades
- Low embodied carbon — 3.4 kg CO₂/kg, better than 91% of stainless steel grades
- Conducts heat well — 24.9 W/m·K (14.4 BTU/hr·ft·°F), better than 87% of stainless steel grades
Limitations
- Needs corrosion protection — 32/100, worse than 99% of stainless steel grades
- Difficult to weld — 30/100, worse than 88% of stainless steel grades
- Limited ductility — 19%, worse than 81% of stainless steel grades
S42035-QT650 properties
Typical room-temperature values for S42035-QT650; 13 are specific to this condition. Other listed values are S42035 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
S42035-QT650 has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 83% of stainless steel grades. It melts at 1,454°C (2,649 °F).
Mechanical15
S42035-QT650 has a yield strength of 690 MPa (100 ksi) and a tensile strength of 860 MPa (125 ksi) — stronger than 92% of stainless steel grades. Elongation at break is 19% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
S42035-QT650 is rated for continuous service to 550°C (1,022 °F). It conducts heat at 24.9 W/m·K (14.4 BTU/hr·ft·°F), better than 87% of stainless steel grades. Thermal expansion is 10.3 µm/m·K (5.72 µin/in·°F).
Electrical3
S42035-QT650 conducts electricity at 3.1 % IACS, better than 99% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is poor (32/100), worse than 99% of stainless steel grades.
Sustainability4
Producing a kilogram of S42035-QT650 takes about 48 MJ of energy and emits 3.4 kg of CO₂ — less than 85% of stainless steel grades. Typical recycled content is 60%.
Manufacturability7
S42035-QT650's machinability is fair (40/100, better than 72% of stainless steel grades); weldability poor (30/100); formability fair (38/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with S42035-QT650
Is S42035 easy to machine?
Machine in the annealed condition with rigid setups, sharp positive-rake carbide and generous coolant; the alloy work-hardens and produces stringy chips, so keep feed constant and avoid dwelling.
Can S42035 be welded?
Weldable only with 200–315 °C preheat, matching 410/420 or austenitic 309/316 filler, and immediate post-weld temper at 700–760 °C; otherwise the HAZ cracks from untempered martensite.
Can S42035 be formed, bent or molded?
Cold forming is limited to gentle bends in the annealed state (bend radius ≥2t); hot work at 1100–1200 °C and slow-cool or anneal immediately after forging.
What surface finishes work on S42035?
Passivate per ASTM A967 (citric or nitric) after machining; can be mirror polished, hard chrome plated, nitrided or black oxided — do not use processes that exceed the tempering temperature.
S42035 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 |
|---|---|---|
| Cmodified 420 carbon band; sets attainable hardness | 0.25 – 0.4 | 0.32 |
| Cr | 12 – 14 | 13 |
| Mn | ≤ 1 | 0.5 |
| Si | ≤ 1 | 0.4 |
| Nioptional addition for hardenability/toughness | ≤ 0.75 | 0.3 |
| Mooptional; improves temper resistance and pitting | ≤ 0.6 | 0.25 |
| P | ≤ 0.04 | — |
| Scontrolled sulfur to aid machinability | ≤ 0.03 | 0.02 |
| N | ≤ 0.06 | — |
| Fe | balance | — |
S42035-QT650 — frequently asked
What is S42035-QT650 used for?
S42035-QT650 is typically used for valve trim, pump shafts and general corrosion-resistant hardware. In short: hardenable 13% Cr grade; machines better than austenitics; poor weldability without preheat.
What is the yield strength of S42035-QT650?
S42035-QT650 has a typical yield strength of 690 MPa (100 ksi) and a tensile strength of 860 MPa (125 ksi) — stronger than 92% of stainless steel grades. Strength varies by condition: see the 8 listed tempers.
Is S42035-QT650 easy to machine?
Not especially — machinability is rated fair (40/100, better than 72% of stainless steel grades). Machine in the annealed condition with rigid setups, sharp positive-rake carbide and generous coolant; the alloy work-hardens and produces stringy chips, so keep feed constant and avoid dwelling.
Can S42035-QT650 be welded?
Not readily — weldability is rated poor (30/100). Weldable only with 200–315 °C preheat, matching 410/420 or austenitic 309/316 filler, and immediate post-weld temper at 700–760 °C; otherwise the HAZ cracks from untempered martensite.
What surface finishes work on S42035-QT650?
Passivate per ASTM A967 (citric or nitric) after machining; can be mirror polished, hard chrome plated, nitrided or black oxided — do not use processes that exceed the tempering temperature.
Can S42035-QT650 be formed, bent or molded?
Cold forming is limited to gentle bends in the annealed state (bend radius ≥2t); hot work at 1100–1200 °C and slow-cool or anneal immediately after forging.
What is the maximum service temperature of S42035-QT650?
S42035-QT650 is rated for continuous use to about 550°C (1,022 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between S42035-A and S42035-QT205?
A is the default condition — standard stock condition for machining and forming before hardening. QT205: maximum hardness and wear resistance for valve trim, seats and cutting edges. Yield strength is 380 MPa in A versus 1,450 MPa in QT205.
Sources
- ASTM A276/A276M — Stainless Steel Bars and Shapes — ASTM International (2023)
- ASTM A582/A582M — Free-Machining Stainless Steel Bars — ASTM International (2021)
- ASTM A959 — Harmonized Standard Grade Compositions for Wrought Stainless Steels — ASTM International (2022)
- ASM Specialty Handbook: Stainless Steels — ASM International (1994)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- GB/T 1220 (2007)
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.