Stainless Steel CG3M
ASTM CG3M · UNS J92999 · EN 1.4508
CG3M (J92999) is the low-carbon version of CG8M, a cast austenitic stainless steel with higher molybdenum than CF3M, supplied solution annealed at 275 MPa yield, 530 MPa tensile strength, 40% elongation and 150 HB (80 HRB).
Reference datasheet — CG3M 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 SA condition
CG3M tempers and conditions
CG3M is supplied in 3 conditions, soft to hard. SA is the default FabDigit quotes; the values on this page are for it.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
SADefault Solution annealed | Standard supply condition for ASTM A743/A744 CG3M castings; maximum corrosion resistance and ductility. | 275 | 530 | 40 | 150 HB | — |
Spheroidize annealed | Only for non-critical, non-corrosive duty; residual segregation and interdendritic phases lower corrosion resistance and toughness versus solution annealed. | 285 | 520 | 28 | 160 HB | 2.1 % IACS |
hot isostatically pressed then solution annealed | Chosen for pressure-critical pump/valve castings where shrinkage porosity must be closed for higher fatigue life and better radiographic quality. | 285 | 550 | 45 | 150 HB | 2.1 % IACS |
What is CG3M?
CG3M (J92999) is the low-carbon version of CG8M, a cast austenitic stainless steel with higher molybdenum than CF3M, supplied solution annealed at 275 MPa yield, 530 MPa tensile strength, 40% elongation and 150 HB (80 HRB). The low carbon avoids sensitization in as-welded castings, giving a weldability score of 85 and a corrosion resistance score of 74 for aggressive chemical duty. It is available as sand and investment castings, including HIP plus solution-annealed condition. Maximum service temperature is 425 °C, so it is not a heat-resistant grade; CF3M is the lower-cost choice when the extra molybdenum is not required. CG3M has a density of 7.98 g/cm³ (0.288 lb/in³), heavier than 85% of stainless steel grades. It melts at 1,400°C (2,552 °F). CG3M has a yield strength of 275 MPa (39.9 ksi) and a tensile strength of 530 MPa (76.9 ksi) — weaker than 77% of stainless steel grades. Elongation at break is 40% and the elastic modulus is 193 GPa (28 Msi).
What is CG3M used for?
- Welded chemical process castings
- Corrosive fluid handling components
- Pump casings and impellers for acid service
- Valve bodies and bonnets
- Pulp bleach plant fittings
- Scrubber and absorber internals
- Pressure-retaining castings for welded piping systems
Advantages
- Readily welded — 85/100, better than 87% of stainless steel grades
- Good corrosion resistance — 74/100, better than 78% of stainless steel grades
Limitations
- Hard to polish — 60/100, worse than 80% of stainless steel grades
- Limited formability — 25/100, worse than 78% of stainless steel grades
- Low strength — 275 MPa (39.9 ksi), worse than 77% of stainless steel grades
CG3M properties
Typical room-temperature values for CG3M-SA; bars are the position among stainless steel grades.
Physical3
CG3M has a density of 7.98 g/cm³ (0.288 lb/in³), heavier than 85% of stainless steel grades. It melts at 1,400°C (2,552 °F).
Mechanical14
CG3M has a yield strength of 275 MPa (39.9 ksi) and a tensile strength of 530 MPa (76.9 ksi) — weaker than 77% of stainless steel grades. Elongation at break is 40% and the elastic modulus is 193 GPa (28 Msi).
Thermal6
CG3M is rated for continuous service to 425°C (797 °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 16.2 µm/m·K (9 µin/in·°F).
Electrical3
CG3M conducts electricity at 2.1 % IACS, worse than 73% of stainless steel grades.
Chemical & Environmental3
Corrosion resistance is very good (74/100), better than 78% of stainless steel grades.
Sustainability4
Producing a kilogram of CG3M takes about 55 MJ of energy and emits 4.5 kg of CO₂ — more than 50% of stainless steel grades. Typical recycled content is 75%.
Manufacturability8
CG3M's machinability is fair (35/100, better than 51% of stainless steel grades); weldability excellent (85/100); formability poor (25/100).
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. CG3M is highlighted; hover a dot for its name, or open the interactive family chart.
Working with CG3M
Is CG3M easy to machine?
Machine like CF3M/316L cast stainless: rigid setup, sharp positive-rake carbide, low speed with heavy feed, flood coolant and no dwelling to avoid work-hardened glazing.
Can CG3M be welded?
Excellent — GTAW/SMAW with ER316L/E316L-15 (or matching CG3M/ER317L for full Mo match); low carbon means no post-weld solution anneal is needed, keep interpass low and avoid full-ferrite-free deposits to limit hot cracking.
Can CG3M be formed, bent or molded?
Sand or investment cast only; allow ~2.5 % shrinkage with generous risering and chills, then solution anneal and water quench for corrosion service.
CG3M 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 grade, avoids sensitization | ≤ 0.03 | 0.02 |
| Mn | ≤ 1.5 | 0.8 |
| Si | ≤ 1.5 | 1 |
| P | ≤ 0.04 | |
| S | ≤ 0.04 | |
| Cr | 18 – 21 | 19.5 |
| Ni | 9 – 13 | 11 |
| Mohigher than CF3M (2–3 %) | 3 – 4 | 3.5 |
| Fe | balance |
What surface finishes work on CG3M?
Grit blast, pickle and passivate per ASTM A967 (citric or nitric); electropolishing gives the best cleanliness for pulp/chemical duty — no anodizing.
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
Equivalent designations
Standards and trade names that resolve to Stainless Steel CG3M in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- J92999
- EN / DIN / Werkstoff-Nr.
- 1.4508
How much does CG3M cost?
CG3M is a premium-cost stainless steel ($$$), cheaper than about 51% 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.
CG3M — frequently asked
What is CG3M used for?
CG3M is typically used for welded chemical process castings, corrosive fluid handling components, pump casings and impellers for acid service, valve bodies and bonnets, pulp bleach plant fittings and scrubber and absorber internals. In short: weldable high-Mo cast austenitic; low-carbon CG8M; better corrosion than CF3M.
What is the yield strength of CG3M?
CG3M has a typical yield strength of 275 MPa (39.9 ksi) and a tensile strength of 530 MPa (76.9 ksi) — weaker than 77% of stainless steel grades. Strength varies by condition: see the 3 listed tempers.
Is CG3M easy to machine?
Not especially — machinability is rated fair (35/100, better than 51% of stainless steel grades). Machine like CF3M/316L cast stainless: rigid setup, sharp positive-rake carbide, low speed with heavy feed, flood coolant and no dwelling to avoid work-hardened glazing.
Can CG3M be welded?
Yes — weldability is rated excellent (85/100). Excellent — GTAW/SMAW with ER316L/E316L-15 (or matching CG3M/ER317L for full Mo match); low carbon means no post-weld solution anneal is needed, keep interpass low and avoid full-ferrite-free deposits to limit hot cracking.
What surface finishes work on CG3M?
Grit blast, pickle and passivate per ASTM A967 (citric or nitric); electropolishing gives the best cleanliness for pulp/chemical duty — no anodizing.
Can CG3M be formed, bent or molded?
Sand or investment cast only; allow ~2.5 % shrinkage with generous risering and chills, then solution anneal and water quench for corrosion service.
What is the maximum service temperature of CG3M?
CG3M is rated for continuous use to about 425°C (797 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between CG3M-SA and CG3M-AC?
SA is the default condition — standard supply condition for ASTM A743/A744 CG3M castings; maximum corrosion resistance and ductility. AC: only for non-critical, non-corrosive duty; residual segregation and interdendritic phases lower corrosion resistance and toughness versus solution annealed. Yield strength is 275 MPa in SA versus 285 MPa in AC.
How much does CG3M cost?
CG3M is a premium-cost stainless steel ($$$), cheaper than about 51% 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 A743/A743M — Castings, Iron-Chromium, Iron-Chromium-Nickel, Corrosion Resistant, for General Application — ASTM (2019)
- ASTM A744/A744M — Castings, Iron-Chromium-Nickel, Corrosion Resistant, for Severe Service — ASTM (2019)
- Steel Castings Handbook, Supplement 8 — High Alloy Data Sheets, Corrosion Series — SFSA (2004)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.15 — Casting — ASM International (2008)
- UNS J92999 alloy record — SAE/ASTM Unified Numbering System (2018)
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.