Stainless Steel 316C16-AC (Spheroidize annealed)
Heat-treated state
EN 316C16 · ASTM CF3M
Only for non-critical, non-corrosive structural castings; carbide/sigma networks reduce corrosion resistance and toughness.
Values for the AC condition
Other 316C16 tempers and conditions
316C16 is listed in 5 conditions; see the grade overview at 316C16.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
SADefault Solution annealed | Standard supply condition for all pressure-containing castings; maximum corrosion resistance and ductility. | 250 | 530 | 50 | 150 HB | — |
Hot isostatically pressed then solution annealed | Choose for fatigue- or leak-critical valve/pump bodies where shrinkage microporosity must be closed. | 255 | 550 | 55 | 150 HB | 2.2 % IACS |
As-welded deposit | Permitted for this low-carbon grade: field welds and minor foundry repairs stay corrosion-resistant without re-solution treatment. | 255 | 520 | 40 | 160 HB | 2.2 % IACS |
ACThis page Spheroidize annealed | Only for non-critical, non-corrosive structural castings; carbide/sigma networks reduce corrosion resistance and toughness. | 265 | 500 | 32 | 160 HB | 2.2 % IACS |
Centrifugally cast, solution annealed | For cylindrical bodies, sleeves and pipe where the denser, directionally solidified structure raises strength slightly. | 265 | 550 | 45 | 158 HB | 2.2 % IACS |
What is 316C16-AC?
316C16-AC is 316C16 heat treated to AC — only for non-critical, non-corrosive structural castings; carbide/sigma networks reduce corrosion resistance and toughness. 316C16-AC has a yield strength of 265 MPa (38.4 ksi) and a tensile strength of 500 MPa (72.5 ksi) — weaker than 81% of stainless steel grades. Elongation at break is 32% and the elastic modulus is 193 GPa (28 Msi). 316C16-AC has a density of 7.95 g/cm³ (0.287 lb/in³), heavier than 81% of stainless steel grades. It melts at 1,390°C (2,534 °F). SA is the default condition FabDigit quotes; AC is available on request or by drawing note.
Advantages
- Readily welded — 88/100, better than 91% of stainless steel grades
Limitations
- Limited formability — 20/100, worse than 86% of stainless steel grades
- Low strength — 265 MPa (38.4 ksi), worse than 81% of stainless steel grades
- Hard to polish — 60/100, worse than 80% of stainless steel grades
316C16-AC properties
Typical room-temperature values for 316C16-AC; 22 are specific to this condition. Other listed values are 316C16 reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
316C16-AC has a density of 7.95 g/cm³ (0.287 lb/in³), heavier than 81% of stainless steel grades. It melts at 1,390°C (2,534 °F).
Mechanical16
316C16-AC has a yield strength of 265 MPa (38.4 ksi) and a tensile strength of 500 MPa (72.5 ksi) — weaker than 81% of stainless steel grades. Elongation at break is 32% and the elastic modulus is 193 GPa (28 Msi).
Thermal6
316C16-AC is rated for continuous service to 650°C (1,202 °F). It conducts heat at 14.5 W/m·K (8.38 BTU/hr·ft·°F), worse than 72% of stainless steel grades. Thermal expansion is 16 µm/m·K (8.89 µin/in·°F).
Electrical3
316C16-AC conducts electricity at 2.2 % IACS, worse than 61% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (63/100), better than 53% of stainless steel grades.
Sustainability4
Producing a kilogram of 316C16-AC takes about 53 MJ of energy and emits 4.3 kg of CO₂ — less than 67% of stainless steel grades. Typical recycled content is 75%.
Manufacturability8
316C16-AC's machinability is fair (36/100, better than 57% of stainless steel grades); weldability excellent (88/100); formability poor (20/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 316C16-AC
Is 316C16 easy to machine?
Work-hardens and tears: use rigid setups, sharp positive-rake carbide, heavy positive feed (avoid dwelling), 60–110 m/min with flood coolant.
Can 316C16 be welded?
Excellent with GTAW/SMAW using 316L/ER316LSi or CF3M-matching filler; keep interpass <150 °C, no preheat, and post-weld solution treatment is normally unnecessary.
Can 316C16 be formed, bent or molded?
Sand, investment or centrifugal casting; feed generously (long freezing range, ~2.2 % solidification shrinkage) and hold FN 5–20 to avoid hot cracking.
What surface finishes work on 316C16?
Pickle and passivate (ASTM A967) or electropolish after grinding; shot-blast residues and free iron must be removed to restore the passive film.
316C16 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 |
|---|---|---|
| Clow-carbon cast grade (CF3M limit); some BS 3100 editions permit up to 0.07 % for 316C16 | ≤ 0.03 | 0.03 |
| Si | ≤ 1.5 | 1 |
| Mn | ≤ 1.5 | 0.9 |
| P | ≤ 0.04 | 0.03 |
| S | ≤ 0.04 | 0.02 |
| Cr | 17 – 21 | 19 |
| Ni | 9 – 13 | 10.5 |
| Mo | 2 – 3 | 2.5 |
| Febalance; ferrite number normally controlled to FN 5–20 | balance | — |
316C16-AC — frequently asked
What is 316C16-AC used for?
316C16-AC is typically used for welded valve castings, pump housings, seawater and brine service and pharma/food process equipment. In short: low-carbon as-welded CF3M; no post-weld anneal needed; chloride-resistant cast austenitic.
What is the yield strength of 316C16-AC?
316C16-AC has a typical yield strength of 265 MPa (38.4 ksi) and a tensile strength of 500 MPa (72.5 ksi) — weaker than 81% of stainless steel grades. Strength varies by condition: see the 5 listed tempers.
Is 316C16-AC easy to machine?
Not especially — machinability is rated fair (36/100, better than 57% of stainless steel grades). Work-hardens and tears: use rigid setups, sharp positive-rake carbide, heavy positive feed (avoid dwelling), 60–110 m/min with flood coolant.
Can 316C16-AC be welded?
Yes — weldability is rated excellent (88/100). Excellent with GTAW/SMAW using 316L/ER316LSi or CF3M-matching filler; keep interpass <150 °C, no preheat, and post-weld solution treatment is normally unnecessary.
What surface finishes work on 316C16-AC?
Pickle and passivate (ASTM A967) or electropolish after grinding; shot-blast residues and free iron must be removed to restore the passive film.
Can 316C16-AC be formed, bent or molded?
Sand, investment or centrifugal casting; feed generously (long freezing range, ~2.2 % solidification shrinkage) and hold FN 5–20 to avoid hot cracking.
What is the maximum service temperature of 316C16-AC?
316C16-AC 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 316C16-SA and 316C16-AC?
SA is the default condition — standard supply condition for all pressure-containing castings; maximum corrosion resistance and ductility. AC: only for non-critical, non-corrosive structural castings; carbide/sigma networks reduce corrosion resistance and toughness. Yield strength is 250 MPa in SA versus 265 MPa in AC.
Sources
- BS 3100 — Steel castings for general engineering purposes (grade 316C16) — BSI (1991)
- ASTM A351/A351M — Castings, Austenitic, for Pressure-Containing Parts (CF3M) — ASTM (2023)
- ASTM A743/A744 — Corrosion-Resistant Iron-Chromium-Nickel Castings — ASTM (2021)
- ASM Specialty Handbook: Stainless Steels — ASM International (1994)
- Steel Castings Handbook, 6th ed. — Steel Founders' Society of America / ASM (1995)
- ASM Handbook Vol.13B — Corrosion: Materials — ASM International (2005)
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.