Stainless Steel 430F · heat-treated state
Stainless Steel 430F-QT650
Properties of the QT650 condition, compared with the other 430F tempers.
Use the higher-carbon EN 1.4104 variant when moderate strength plus better wear resistance is needed.
What is 430F-QT650?
430F-QT650 is 430F heat treated to QT650 — use the higher-carbon EN 1.4104 variant when moderate strength plus better wear resistance is needed. 430F-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 12% and the elastic modulus is 200 GPa (29 Msi). 430F-QT650 has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 83% of stainless steel grades. It melts at 1,425°C (2,597 °F). Annealed is the default condition FabDigit quotes; QT650 is available on request or by drawing note.
Advantages
- Easy to machine — 60/100, better than 98% of stainless steel grades
- Conducts heat well — 26 W/m·K (15 BTU/hr·ft·°F), better than 96% 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
- High strength — 500 MPa (72.5 ksi), better than 77% of stainless steel grades
Limitations
- Difficult to weld — 20/100, worse than 96% of stainless steel grades
- Limited ductility — 12%, worse than 95% of stainless steel grades
- Hard to polish — 50/100, worse than 94% of stainless steel grades
- Needs corrosion protection — 48/100, worse than 81% of stainless steel grades
- Limited service temperature — 400°C (752 °F), worse than 78% of stainless steel grades
430F-QT650 properties
Typical room-temperature values for 430F-QT650 — 9 properties are specific to this condition; the rest are grade-level values shared by every 430F temper. Each bar shows where the value sits among the stainless steel grades in FabDigit's library — further right is higher.
Physical3
430F-QT650 has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 83% of stainless steel grades. It melts at 1,425°C (2,597 °F).
Mechanical13
430F-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 12% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
430F-QT650 is rated for continuous service to 400°C (752 °F). It conducts heat at 26 W/m·K (15 BTU/hr·ft·°F), better than 96% of stainless steel grades. Thermal expansion is 10.4 µm/m·K (5.78 µin/in·°F).
Electrical3
430F-QT650 conducts electricity at 2.9 % IACS, better than 87% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is fair (48/100), worse than 81% of stainless steel grades.
Sustainability4
Producing a kilogram of 430F-QT650 takes about 50 MJ of energy and emits 3.2 kg of CO₂ — less than 81% of stainless steel grades. Typical recycled content is 70%.
Manufacturability7
430F-QT650's machinability is good (60/100, better than 98% of stainless steel grades); weldability poor (20/100); formability poor (30/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other 430F tempers and conditions
430F is also supplied in 5 other conditions. The full side-by-side table is on the 430F overview.
- AnnealedDefaultStandard stocked condition for automatic-lathe turning and subsequent forming or heat treatment.380 MPa yield · 175 HB
- H&T 40-45 HRCMaximum-hardness condition for wear surfaces, valve seats and small tooling; toughness and corrosion resistance drop.1,000 MPa yield · 43 HRC
- Cold DrawnChoose for straight, close-tolerance bar with higher strength for screw-machine parts and shafts.550 MPa yield · 235 HB
- QT650Use the higher-carbon EN 1.4104 variant when moderate strength plus better wear resistance is needed.500 MPa yield · 22 HRC
Working with 430F-QT650
Is 430F easy to machine?
Excellent free-cutting behavior — run 20–40 % faster than 430, use positive rake carbide, sharp tools and good chip evacuation; sulfides give short chips and clean threads.
Can 430F be welded?
Not recommended: sulfur promotes hot cracking and the HAZ coarsens/embrittles; if unavoidable, preheat 150–250 °C, use 309L filler and post-weld anneal.
Can 430F be formed, bent or molded?
Only light bending, upsetting or knurling — sulfide stringers cause transverse splitting; form generously radiused and avoid cold heading.
What surface finishes work on 430F?
Passivate (ASTM A967 nitric or citric) after machining to reduce sulfide-initiated rust; hard chrome, electroless nickel or black oxide are used where more corrosion or wear resistance is needed; mirror polishing shows inclusion pits.
430F 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 1.4104 runs 0.10–0.17 %C and is hardenable | ≤ 0.12 | 0.08 |
| Si | ≤ 1 | 0.5 |
| Mn | ≤ 1.25 | 0.8 |
| P | ≤ 0.06 | 0.03 |
| Sfree-machining addition; EN 1.4104 0.15–0.35 | ≥ 0.15 | 0.25 |
| Cr | 16 – 18 | 17 |
| Mooptional in S43020; EN 1.4104 specifies 0.20–0.60 | ≤ 0.6 | 0.4 |
| Niresidual, not specified in ASTM A582 | ≤ 0.5 | 0.3 |
| Fe | balance | — |
430F-QT650 — frequently asked
What is 430F-QT650 used for?
430F-QT650 is typically used for machined fittings, solenoid cores and armatures, valve components, shafts and pins, screw-machine fasteners and sensor and instrument bodies. In short: free-machining ferritic stainless.
What is the yield strength of 430F-QT650?
430F-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 6 listed tempers.
Is 430F-QT650 easy to machine?
Reasonably — machinability is rated good (60/100, better than 98% of stainless steel grades). Excellent free-cutting behavior — run 20–40 % faster than 430, use positive rake carbide, sharp tools and good chip evacuation; sulfides give short chips and clean threads.
Can 430F-QT650 be welded?
Not readily — weldability is rated poor (20/100). Not recommended: sulfur promotes hot cracking and the HAZ coarsens/embrittles; if unavoidable, preheat 150–250 °C, use 309L filler and post-weld anneal.
What surface finishes work on 430F-QT650?
Passivate (ASTM A967 nitric or citric) after machining to reduce sulfide-initiated rust; hard chrome, electroless nickel or black oxide are used where more corrosion or wear resistance is needed; mirror polishing shows inclusion pits.
Can 430F-QT650 be formed, bent or molded?
Only light bending, upsetting or knurling — sulfide stringers cause transverse splitting; form generously radiused and avoid cold heading.
What is the maximum service temperature of 430F-QT650?
430F-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.
What is the difference between 430F Annealed and 430F-QT650?
Annealed is the default condition — standard stocked condition for automatic-lathe turning and subsequent forming or heat treatment. QT650: use the higher-carbon EN 1.4104 variant when moderate strength plus better wear resistance is needed. Yield strength is 380 MPa in Annealed versus 500 MPa in QT650.
Can FabDigit make parts in 430F-QT650?
Yes — 430F-QT650 is available for CNC machining with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM A582/A582M — Free-Machining Stainless Steel Bars — ASTM (2021)
- EN 10088-3 (X14CrMoS17, 1.4104) — CEN (2014)
- JIS G 4303 (SUS430F) — JSA (2021)
- GB/T 1220 (Y1Cr17) — SAC (2007)
- ASM Specialty Handbook: Stainless Steels — ASM International (1994)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels — ASM International (1990)
- Free-machining ferritic/martensitic stainless bar datasheets (1.4104) — Sandvik / Outokumpu (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.