Stainless Steel 1.4308-AC (Spheroidize annealed)
Heat-treated state
EN 1.4308 · UNS J92600 · ASTM CF8
Only for non-critical, non-corrosive structural or decorative castings — carbide networks reduce corrosion resistance and toughness.
Values for the AC condition
Other 1.4308 tempers and conditions
1.4308 is listed in 4 conditions; see the grade overview at 1.4308.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
pressure-containing certified casting (min. spec values) | Order this when ASME B16.34 / A351 certification with guaranteed minima and hydro/RT testing is required. | 205 | 485 | 35 | 160 HB | 2.4 % IACS |
STDefault Solution annealed | Standard delivery condition for all pressure and corrosion-service castings; carbides dissolved for maximum corrosion resistance and ductility. | 250 | 520 | 50 | 140 HB | 2.4 % IACS |
ACThis page Spheroidize annealed | Only for non-critical, non-corrosive structural or decorative castings — carbide networks reduce corrosion resistance and toughness. | 260 | 500 | 32 | 160 HB | 2.4 % IACS |
Centrifugally cast tube, solution annealed | Centrifugally cast pipe/sleeves (ASTM A451/A452 class) — dense, defect-free wall with the highest as-cast strength for this grade. | 275 | 550 | 45 | 150 HB | 2.4 % IACS |
What is 1.4308-AC?
1.4308-AC is 1.4308 heat treated to AC — only for non-critical, non-corrosive structural or decorative castings — carbide networks reduce corrosion resistance and toughness. 1.4308-AC has a yield strength of 260 MPa (37.7 ksi) and a tensile strength of 500 MPa (72.5 ksi) — weaker than 84% of stainless steel grades. Elongation at break is 32% and the elastic modulus is 195 GPa (28.3 Msi). 1.4308-AC has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 65% of stainless steel grades. It melts at 1,400°C (2,552 °F). ST is the default condition FabDigit quotes; AC is available on request or by drawing note.
Limitations
- Low strength — 260 MPa (37.7 ksi), worse than 84% of stainless steel grades
- Limited formability — 22/100, worse than 82% of stainless steel grades
- Needs corrosion protection — 52/100, worse than 76% of stainless steel grades
1.4308-AC properties
Typical room-temperature values for 1.4308-AC; 22 are specific to this condition. Other listed values are 1.4308 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
1.4308-AC has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 65% of stainless steel grades. It melts at 1,400°C (2,552 °F).
Mechanical16
1.4308-AC has a yield strength of 260 MPa (37.7 ksi) and a tensile strength of 500 MPa (72.5 ksi) — weaker than 84% of stainless steel grades. Elongation at break is 32% and the elastic modulus is 195 GPa (28.3 Msi).
Thermal6
1.4308-AC is rated for continuous service to 600°C (1,112 °F). It conducts heat at 16 W/m·K (9.24 BTU/hr·ft·°F), better than 58% of stainless steel grades. Thermal expansion is 17 µm/m·K (9.44 µin/in·°F).
Electrical3
1.4308-AC conducts electricity at 2.4 % IACS, better than 67% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is fair (52/100), worse than 76% of stainless steel grades.
Sustainability4
Producing a kilogram of 1.4308-AC takes about 60 MJ of energy and emits 5 kg of CO₂ — more than 70% of stainless steel grades. Typical recycled content is 70%.
Manufacturability8
1.4308-AC's machinability is fair (38/100, better than 63% of stainless steel grades); weldability very good (70/100); formability poor (22/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 1.4308-AC
Is 1.4308 easy to machine?
Gummy and work-hardening: use sharp positive-rake carbide, rigid setup, 60–120 m/min, heavy positive feed to cut beneath the hardened layer, plenty of coolant.
Can 1.4308 be welded?
Readily welded by GTAW/SMAW with 308/308L filler; keep interpass low, no preheat, and solution anneal after major repair welds to restore corrosion resistance.
Can 1.4308 be formed, bent or molded?
Sand, investment and centrifugal casting all work well; allow ~2% solidification shrinkage, use generous risers on heavy sections and control δ-ferrite to 5–15 FN for hot-crack resistance.
What surface finishes work on 1.4308?
Pickle/passivate (ASTM A967) or electropolish after machining; shot blasting improves appearance but leaves surface iron that must be removed to avoid rust bloom.
1.4308 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 1.4308 limits C ≤ 0.07 | ≤ 0.08 | 0.06 |
| SiEN: Si ≤ 1.5 | ≤ 2 | 1.2 |
| Mn | ≤ 1.5 | 1 |
| P | ≤ 0.04 | 0.03 |
| SEN: S ≤ 0.030 | ≤ 0.04 | 0.02 |
| CrEN 1.4308: 18.0–20.0 | 18 – 21 | 19.5 |
| Ni | 8 – 11 | 9.5 |
| Moresidual only | ≤ 0.5 | 0.2 |
| Fe | balance | — |
1.4308-AC — frequently asked
What is 1.4308-AC used for?
1.4308-AC is typically used for pump bodies, valve castings and food and chemical processing fittings. In short: cast 304 workhorse; lowest-cost cast austenitic; very high as-cast ductility.
What is the yield strength of 1.4308-AC?
1.4308-AC has a typical yield strength of 260 MPa (37.7 ksi) and a tensile strength of 500 MPa (72.5 ksi) — weaker than 84% of stainless steel grades. Strength varies by condition: see the 4 listed tempers.
Is 1.4308-AC easy to machine?
Not especially — machinability is rated fair (38/100, better than 63% of stainless steel grades). Gummy and work-hardening: use sharp positive-rake carbide, rigid setup, 60–120 m/min, heavy positive feed to cut beneath the hardened layer, plenty of coolant.
Can 1.4308-AC be welded?
Yes — weldability is rated very good (70/100). Readily welded by GTAW/SMAW with 308/308L filler; keep interpass low, no preheat, and solution anneal after major repair welds to restore corrosion resistance.
What surface finishes work on 1.4308-AC?
Pickle/passivate (ASTM A967) or electropolish after machining; shot blasting improves appearance but leaves surface iron that must be removed to avoid rust bloom.
Can 1.4308-AC be formed, bent or molded?
Sand, investment and centrifugal casting all work well; allow ~2% solidification shrinkage, use generous risers on heavy sections and control δ-ferrite to 5–15 FN for hot-crack resistance.
What is the maximum service temperature of 1.4308-AC?
1.4308-AC is rated for continuous use to about 600°C (1,112 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 1.4308-ST and 1.4308 ST-CENT?
ST is the default condition — standard delivery condition for all pressure and corrosion-service castings; carbides dissolved for maximum corrosion resistance and ductility. ST-CENT: centrifugally cast pipe/sleeves (ASTM A451/A452 class) — dense, defect-free wall with the highest as-cast strength for this grade. Yield strength is 250 MPa in ST versus 275 MPa in ST-CENT.
Sources
- EN 10213 — Steel castings for pressure purposes — CEN (2016)
- EN 10283 — Corrosion resistant steel castings — CEN (2010)
- ASTM A351/A351M — Castings, Austenitic, for Pressure-Containing Parts — ASTM (2020)
- ASTM A743/A743M — Castings, Iron-Chromium-Nickel, Corrosion Resistant — ASTM (2021)
- ASM Specialty Handbook: Stainless Steels — ASM International (1994)
- ASM Handbook Vol. 15 — Casting — ASM International (2008)
- Steel Castings Handbook — Steel Founders' Society of America (1995)
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.