Stainless Steel CK35MN
ASTM CK35MN
CK35MN is a high-manganese, high chromium-nickel cast austenitic stainless steel developed as a manganese-alloyed alternative to CK20 for high-temperature service.
Reference datasheet — CK35MN is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the AC condition
CK35MN tempers and conditions
CK35MN is supplied in 4 conditions, soft to hard. AC is the default FabDigit quotes; the values on this page are for it.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution annealed | Choose when maximum ductility, toughness and aqueous corrosion resistance are needed before service; dissolves the as-cast carbide network. | 230 | 480 | 38 | 170 HB | 2 % IACS |
Statically sand/investment cast shape | Standard route for valve bodies, grates, fixtures and complex furnace hardware where section thickness varies. | 245 | 495 | 30 | 183 HB | 2 % IACS |
ACDefault Spheroidize annealed | Standard supply condition for heat-resistant service — carbides in the as-cast network actually aid creep strength. | 250 | 500 | 30 | 185 HB | 2 % IACS |
Stress relieved | Use on large or welded castings to relieve residual stress and reduce distortion before machining; does not restore ductility. | 250 | 495 | 26 | 187 HB | 2.1 % IACS |
Supply forms, finishes and certifications
Ways CK35MN is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
CC | Centrifugally cast | Surface finish |
What is CK35MN?
CK35MN is a high-manganese, high chromium-nickel cast austenitic stainless steel developed as a manganese-alloyed alternative to CK20 for high-temperature service. Castings are used up to 1050 °C and provide 250 MPa yield, 500 MPa tensile, 30 % elongation and about 185 HB, with manganese partly replacing nickel to reduce alloy cost. Aqueous corrosion resistance is limited compared with CK20, no common UNS designation is on file so availability depends on the foundry, and the high-carbon austenite is prone to carbide precipitation in the heat-affected zone. CK20 remains the reference grade when oxidation life and documentation matter most. CK35MN has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 65% of stainless steel grades. It melts at 1,370°C (2,498 °F). CK35MN 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 30% and the elastic modulus is 193 GPa (28 Msi).
What is CK35MN used for?
- High-temperature furnace castings
- Heat-resistant process equipment
- Heat treatment fixtures and trays
- Furnace rollers and rails
- Radiant tube and burner parts
- Kiln fittings
Advantages
- High service temperature — 1,050°C (1,922 °F), better than 91% of stainless steel grades
Limitations
- Limited formability — 10/100, worse than 95% of stainless steel grades
- Low strength — 250 MPa (36.3 ksi), worse than 91% of stainless steel grades
- Hard to polish — 55/100, worse than 89% of stainless steel grades
- Difficult to weld — 40/100, worse than 83% of stainless steel grades
- Low fracture toughness — 85 MPa·√m (77.4 ksi·√in), worse than 77% of stainless steel grades
CK35MN properties
Typical room-temperature values for CK35MN-AC; bars are the position among stainless steel grades.
Physical3
CK35MN has a density of 7.75 g/cm³ (0.28 lb/in³), lighter than 65% of stainless steel grades. It melts at 1,370°C (2,498 °F).
Mechanical15
CK35MN 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 30% and the elastic modulus is 193 GPa (28 Msi).
Thermal6
CK35MN is rated for continuous service to 1,050°C (1,922 °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 15.9 µm/m·K (8.83 µin/in·°F).
Electrical3
CK35MN conducts electricity at 2 % IACS, worse than 77% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is good (55/100), worse than 71% of stainless steel grades.
Sustainability4
Producing a kilogram of CK35MN takes about 60 MJ of energy and emits 4.5 kg of CO₂ — more than 70% of stainless steel grades. Typical recycled content is 65%.
Manufacturability8
CK35MN's machinability is poor (28/100, worse than 79% of stainless steel grades); weldability fair (40/100); formability not recommended (10/100).
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. CK35MN is highlighted; hover a dot for its name, or open the interactive family chart.
Working with CK35MN
Is CK35MN easy to machine?
Rigid setups, low speed with heavy positive feed, sharp carbide or ceramic tooling and flood coolant; the work-hardening austenite plus interdendritic carbides cause rapid edge wear, so avoid dwelling and interrupted light cuts.
Can CK35MN be welded?
Weldable with matching 25Cr-20Ni (ER310/E310-type) filler using low heat input, small stringer beads and interpass temperature control; fully austenitic ferrite-free weld metal is hot-crack sensitive and the high-carbon base is prone to HAZ carbide precipitation.
Can CK35MN be formed, bent or molded?
A casting grade only — not intended for cold forming; design generous fillets, uniform sections and adequate risers, allow ~2 % solidification shrinkage and avoid hot-tear-prone sharp corners.
CK35MN 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 |
|---|---|---|
| Chigh carbon for creep strength; verify range against the current ASTM A351/A743 edition | 0.25 – 0.35 | 0.3 |
| Mnmanganese-alloyed feature of this grade (partial Ni substitute / austenite stabilizer) | 1.5 – 4 | 2.5 |
| Si | ≤ 1.5 | 1 |
| CrCK-family chromium level, as CK20 | 23 – 27 | 25 |
| Ni | 18 – 22 | 20 |
| Moresidual only | ≤ 0.5 | 0.2 |
| Nnitrogen may be specified to strengthen the austenite | ≤ 0.2 | 0.1 |
| P | ≤ 0.04 | |
| S | ≤ 0.04 | |
| Fe | balance |
What surface finishes work on CK35MN?
Grit blast plus pickle/passivate to remove casting scale; shot-peening or grinding improves fatigue, and aluminizing or diffusion coating extends life above 1000 °C in sulphur-bearing gas.
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).
Passivation
Organic Coating
Thermal Spray
How much does CK35MN cost?
CK35MN is a high-cost stainless steel ($$$$), pricier than about 78% 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.
CK35MN — frequently asked
What is CK35MN used for?
CK35MN is typically used for high-temperature furnace castings, heat-resistant process equipment, heat treatment fixtures and trays, furnace rollers and rails, radiant tube and burner parts and kiln fittings. In short: manganese-alloyed CK20 substitute; lower nickel content; 1050 °C oxidation service.
What is the yield strength of CK35MN?
CK35MN 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 4 listed tempers.
Is CK35MN easy to machine?
Not especially — machinability is rated poor (28/100, worse than 79% of stainless steel grades). Rigid setups, low speed with heavy positive feed, sharp carbide or ceramic tooling and flood coolant; the work-hardening austenite plus interdendritic carbides cause rapid edge wear, so avoid dwelling and interrupted light cuts.
Can CK35MN be welded?
With care — weldability is rated fair (40/100). Weldable with matching 25Cr-20Ni (ER310/E310-type) filler using low heat input, small stringer beads and interpass temperature control; fully austenitic ferrite-free weld metal is hot-crack sensitive and the high-carbon base is prone to HAZ carbide precipitation.
What surface finishes work on CK35MN?
Grit blast plus pickle/passivate to remove casting scale; shot-peening or grinding improves fatigue, and aluminizing or diffusion coating extends life above 1000 °C in sulphur-bearing gas.
Can CK35MN be formed, bent or molded?
A casting grade only — not intended for cold forming; design generous fillets, uniform sections and adequate risers, allow ~2 % solidification shrinkage and avoid hot-tear-prone sharp corners.
What is the maximum service temperature of CK35MN?
CK35MN is rated for continuous use to about 1,050°C (1,922 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between CK35MN-AC and CK35MN-SA?
AC is the default condition — standard supply condition for heat-resistant service — carbides in the as-cast network actually aid creep strength. SA: choose when maximum ductility, toughness and aqueous corrosion resistance are needed before service; dissolves the as-cast carbide network. Yield strength is 250 MPa in AC versus 230 MPa in SA.
How much does CK35MN cost?
CK35MN is a high-cost stainless steel ($$$$), pricier than about 78% 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.
Sources
- ASTM A351/A351M — Castings, Austenitic, for Pressure-Containing Parts — ASTM International (2018)
- ASTM A743/A743M — Castings, Iron-Chromium, Iron-Chromium-Nickel, Corrosion Resistant, for General Application — ASTM International (2019)
- High Alloy Data Sheets, Heat Series (CK-type / HK-type alloys) — Steel Founders' Society of America (2004)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.13B — Corrosion: Materials — ASM International (2005)
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.