Stainless Steel 430F
AISI/SAE 430F · UNS S43020 · ASTM A582 · EN 1.4104, 1.4105 · JIS SUS430F
430F (1.4105 / 1.4104, X6CrMoS17, S43020, SUS430F) is a free-machining ferritic stainless with molybdenum and sulfur additions, covered by ASTM A582 and stocked annealed, hot rolled, cold drawn, ground-and-polished, QT650 and hardened to 40–45 HRC.
Values for the Annealed condition
430F tempers and conditions
430F is supplied in 6 conditions, soft to hard. Annealed is the default FabDigit quotes; the values on this page are for it.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AnnealedDefault softened bar/wire (EN +A) | Standard stocked condition for automatic-lathe turning and subsequent forming or heat treatment. | 380 | 550 | 25 | 175 HB | — |
Hot Rolled (hot finished, unannealed bar) | Cheapest large-diameter bar stock when the part is fully machined and only moderate strength is needed. | 400 | 580 | 22 | 190 HB | 2.9 % IACS |
Quenched & tempered +QT650 | Use the higher-carbon EN 1.4104 variant when moderate strength plus better wear resistance is needed. | 500 | 750 | 12 | 22 HRC | 2.9 % IACS |
annealed and cold drawn bar (EN +C) | Choose for straight, close-tolerance bar with higher strength for screw-machine parts and shafts. | 550 | 660 | 15 | 235 HB | — |
Cold drawn, ground and polished bar (h9/h10 shafting) | Pick when the as-supplied OD is a functional surface — valve stems, guide pins, small shafts. | 550 | 660 | 15 | 22 HRC | 2.9 % IACS |
Hardened & tempered to 40–45 HRC | Maximum-hardness condition for wear surfaces, valve seats and small tooling; toughness and corrosion resistance drop. | 1,000 | 1,300 | 6 | 43 HRC | — |
What is 430F?
430F (1.4105 / 1.4104, X6CrMoS17, S43020, SUS430F) is a free-machining ferritic stainless with molybdenum and sulfur additions, covered by ASTM A582 and stocked annealed, hot rolled, cold drawn, ground-and-polished, QT650 and hardened to 40–45 HRC. It is used for precision turned parts and magnetically soft components, with a machinability score of 72 and 380 MPa yield, 550 MPa tensile, 25% elongation and 175 HB in the default condition, usable to 650 °C. Sulfide stringers cut corrosion resistance, block welding and limit formability (score 30). Use 430 for welded or deep-drawn parts and 303 where more corrosion resistance is needed. 430F 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). 430F has a yield strength of 380 MPa (55.1 ksi) and a tensile strength of 550 MPa (79.8 ksi) — stronger than 52% of stainless steel grades. Elongation at break is 25% and the elastic modulus is 200 GPa (29 Msi).
What is 430F used for?
- Machined fittings
- Solenoid cores and armatures
- Valve components
- Shafts and pins
- Screw-machine fasteners
- Sensor and instrument bodies
- Nozzles and adapters
Advantages
- Easy to machine — 72/100, better than 99% 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
Limitations
- Difficult to weld — 20/100, worse than 95% of stainless steel grades
- Hard to polish — 50/100, worse than 93% of stainless steel grades
- Needs corrosion protection — 48/100, worse than 80% of stainless steel grades
430F properties
Typical room-temperature values for 430F-Annealed; bars are the position among stainless steel grades.
Physical3
430F 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 has a yield strength of 380 MPa (55.1 ksi) and a tensile strength of 550 MPa (79.8 ksi) — stronger than 52% of stainless steel grades. Elongation at break is 25% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
430F is rated for continuous service to 650°C (1,202 °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 conducts electricity at 2.9 % IACS, better than 87% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is fair (48/100), worse than 80% of stainless steel grades.
Sustainability4
Producing a kilogram of 430F takes about 50 MJ of energy and emits 3.2 kg of CO₂ — less than 80% of stainless steel grades. Typical recycled content is 70%.
Manufacturability7
430F's machinability is very good (72/100, better than 99% of stainless steel grades); weldability poor (20/100); formability poor (30/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the stainless steel family
Yield strength against density for every stainless steel grade FabDigit runs. 430F is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 430F
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.
Manufacturability
The process limits FabDigit applies to 430F. Every 430F part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
CNC machining
| Machinability | Excellent72 / 100 |
|---|---|
| ISO material group | M.4 |
| Cutting speed (rough / finish) | 140 / 170 m/min |
| Minimum wall | 0.8 mm |
| Minimum internal radius | 1.5 mm |
| Drill depth limit | 4× diameter |
| Best surface (machined / polished) | Ra 1.6 / — |
| Hardenable after machining | No |
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 |
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.
Surface treatments FabDigit runs on stainless steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Plating
Organic Coating
CVD Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Stainless Steel 430F in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- S43020
- ASTM
- A582
- EN / DIN / Werkstoff-Nr.
- 1.41041.4105X6CrMoS17
- GB (China)
- Y1Cr17
- JIS
- SUS430F
How much does 430F cost?
430F is a standard-cost stainless steel ($$), cheaper than about 60% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
430F — frequently asked
What is 430F used for?
430F 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?
430F has a typical yield strength of 380 MPa (55.1 ksi) and a tensile strength of 550 MPa (79.8 ksi) — stronger than 52% of stainless steel grades. Strength varies by condition: see the 6 listed tempers.
Is 430F easy to machine?
Yes — machinability is rated very good (72/100, better than 99% 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 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?
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 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?
430F is rated for continuous use to about 650°C (1,202 °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.
How much does 430F cost?
430F is a standard-cost stainless steel ($$), cheaper than about 60% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Can FabDigit make parts in 430F?
Yes — 430F is available for CNC machining; every part is priced by an engineer rather than instantly. 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; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.