Stainless Steel CF16F-AC (Spheroidize annealed)
Heat-treated state
ASTM CF16F · UNS J92701
Non-standard shop condition for lightly loaded, non-corrosive machined parts; carbides at grain boundaries lower ductility and corrosion resistance, so A743 acceptance requires the HT condition.
Values for the AC condition
Other CF16F tempers and conditions
CF16F is listed in 2 conditions; see the grade overview at CF16F.
- HT
- AC
Compare all 2 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
HTDefault Solution heat treated (≈1040 °C, water quenched) per ASTM A743 | Standard supply condition for A743 CF-16F castings; use when the mechanical minimums and best available corrosion resistance are required. | 240 | 505 | 38 | 150 HB | — |
ACThis page Spheroidize annealed | Non-standard shop condition for lightly loaded, non-corrosive machined parts; carbides at grain boundaries lower ductility and corrosion resistance, so A743 acceptance requires the HT condition. | 250 | 500 | 25 | 160 HB | 2.4 % IACS |
What is CF16F-AC?
CF16F-AC is CF16F heat treated to AC — non-standard shop condition for lightly loaded, non-corrosive machined parts; carbides at grain boundaries lower ductility and corrosion resistance, so A743 acceptance requires the HT condition. CF16F-AC has a yield strength of 250 MPa (36.3 ksi) and a tensile strength of 500 MPa (72.5 ksi) — weaker than 91% of stainless steel grades. Elongation at break is 25% and the elastic modulus is 193 GPa (28 Msi). CF16F-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). HT is the default condition FabDigit quotes; AC is available on request or by drawing note.
Advantages
- Easy to machine — 55/100, better than 94% of stainless steel grades
Limitations
- Difficult to weld — 20/100, worse than 95% of stainless steel grades
- Limited formability — 10/100, worse than 95% of stainless steel grades
- Hard to polish — 50/100, worse than 93% of stainless steel grades
- Low strength — 250 MPa (36.3 ksi), worse than 91% of stainless steel grades
- Needs corrosion protection — 42/100, worse than 90% of stainless steel grades
CF16F-AC properties
Typical room-temperature values for CF16F-AC; 23 are specific to this condition. Other listed values are CF16F reference data and may not represent this condition. Bars are the position among stainless steel grades.
Physical3
CF16F-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).
Mechanical15
CF16F-AC has a yield strength of 250 MPa (36.3 ksi) and a tensile strength of 500 MPa (72.5 ksi) — weaker than 91% of stainless steel grades. Elongation at break is 25% and the elastic modulus is 193 GPa (28 Msi).
Thermal6
CF16F-AC is rated for continuous service to 600°C (1,112 °F). It conducts heat at 16.2 W/m·K (9.36 BTU/hr·ft·°F), better than 64% of stainless steel grades. Thermal expansion is 17 µm/m·K (9.44 µin/in·°F).
Electrical3
CF16F-AC conducts electricity at 2.4 % IACS, better than 67% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is fair (42/100), worse than 90% of stainless steel grades.
Sustainability4
Producing a kilogram of CF16F-AC takes about 53 MJ of energy and emits 5.2 kg of CO₂ — less than 67% of stainless steel grades. Typical recycled content is 75%.
Manufacturability8
CF16F-AC's machinability is good (55/100, better than 94% of stainless steel grades); weldability poor (20/100); formability not recommended (10/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with CF16F-AC
Is CF16F easy to machine?
Best-machining member of the CF family — run 30–50 % higher feeds/speeds than CF8, use sharp positive-rake carbide, rigid setups and flood coolant; still work-hardens if dwelled.
Can CF16F be welded?
Avoid fusion welding: selenium and high phosphorus promote hot cracking and porosity; if repair is unavoidable use 309/312 filler, low heat input, and re-solution treat.
Can CF16F be formed, bent or molded?
Sand or investment cast with generous risering; good fluidity for thin valve/fitting sections, then solution treat at ~1040 °C and water quench.
What surface finishes work on CF16F?
Pickle and passivate (nitric or citric) after machining; expect Se-inclusion streaking on mirror polish and slightly lower passive-film quality than CF8.
CF16F 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 |
|---|---|---|
| C | ≤ 0.16 | 0.12 |
| Mn | ≤ 1.5 | 1 |
| Si | ≤ 2 | 1.3 |
| Pdeliberately high to aid chip breaking | ≤ 0.17 | 0.12 |
| S | ≤ 0.04 | 0.02 |
| Sefree-machining addition | 0.2 – 0.35 | 0.28 |
| Cr | 18 – 21 | 19.5 |
| Ni | 9 – 12 | 10.5 |
| Moresidual only | ≤ 0.5 | 0.2 |
| Fe | balance | — |
CF16F-AC — frequently asked
What is CF16F-AC used for?
CF16F-AC is typically used for machined valve trim, fittings requiring extensive drilling/tapping and small precision castings. In short: best-machining CF grade; free-machining cast austenitic; not for welded parts.
What is the yield strength of CF16F-AC?
CF16F-AC has a typical yield strength of 250 MPa (36.3 ksi) and a tensile strength of 500 MPa (72.5 ksi) — weaker than 91% of stainless steel grades. Strength varies by condition: see the 2 listed tempers.
Is CF16F-AC easy to machine?
Reasonably — machinability is rated good (55/100, better than 94% of stainless steel grades). Best-machining member of the CF family — run 30–50 % higher feeds/speeds than CF8, use sharp positive-rake carbide, rigid setups and flood coolant; still work-hardens if dwelled.
Can CF16F-AC be welded?
Not readily — weldability is rated poor (20/100). Avoid fusion welding: selenium and high phosphorus promote hot cracking and porosity; if repair is unavoidable use 309/312 filler, low heat input, and re-solution treat.
What surface finishes work on CF16F-AC?
Pickle and passivate (nitric or citric) after machining; expect Se-inclusion streaking on mirror polish and slightly lower passive-film quality than CF8.
Can CF16F-AC be formed, bent or molded?
Sand or investment cast with generous risering; good fluidity for thin valve/fitting sections, then solution treat at ~1040 °C and water quench.
What is the maximum service temperature of CF16F-AC?
CF16F-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 CF16F-HT and CF16F-AC?
HT is the default condition — standard supply condition for A743 CF-16F castings; use when the mechanical minimums and best available corrosion resistance are required. AC: non-standard shop condition for lightly loaded, non-corrosive machined parts; carbides at grain boundaries lower ductility and corrosion resistance, so A743 acceptance requires the HT condition. Yield strength is 240 MPa in HT versus 250 MPa in AC.
Sources
- ASTM A743/A743M — Castings, Iron-Chromium, Iron-Chromium-Nickel, Corrosion Resistant, for General Application (grade CF-16F) — ASTM International (2021)
- SAE/ASTM Unified Numbering System for Metals and Alloys (UNS J92701) — SAE/ASTM (2017)
- ASM Specialty Handbook: Stainless Steels — Cast Corrosion-Resistant Alloys — ASM International (1994)
- ASM Handbook Vol.1: Properties and Selection — Irons, Steels, and High-Performance Alloys — ASM International (1990)
- Steel Founders' Society of America — High Alloy Data Sheets, Corrosion Series — SFSA (2004)
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.