Steel SCCrM3
SCCrM3 is a higher-alloy chromium-molybdenum cast steel in the JIS G5111 family, used where SCCrM1 no longer provides enough strength.
Reference datasheet — SCCrM3 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 QT condition
SCCrM3 tempers and conditions
SCCrM3 is supplied in 5 conditions, soft to hard. QT is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution annealed | Pick for maximum machinability and dimensional stability before final heat treatment or when strength is not critical. | 400 | 620 | 20 | 185 HB | — |
Stress relieved | Interim foundry condition for rough machining, weld repair and dimensional stabilisation; final Q&T or N+T is still required for JIS G5111 acceptance. | 480 | 760 | 10 | 20 HRC | 8 % IACS |
normalized and tempered | Use for large or complex castings where quenching risks cracking; gives uniform mid-range strength through heavy sections. | 620 | 830 | 12 | 23 HRC | — |
QTDefault Quenched and tempered | Standard supply condition meeting the JIS G5111 SCCrM3 minima (≈685 MPa PS / 880 MPa TS); the default choice for high-load structural and pressure-bearing castings. | 720 | 900 | 9 | 27 HRC | — |
low-temper high-strength condition | Specify when wear resistance and maximum strength matter more than ductility, e.g. gear blanks and sprocket castings; check section size for hardenability. | 900 | 1,080 | 6 | 35 HRC | — |
What is SCCrM3?
SCCrM3 is a higher-alloy chromium-molybdenum cast steel in the JIS G5111 family, used where SCCrM1 no longer provides enough strength. In the default condition it gives 720 MPa yield, 900 MPa tensile, 9 % elongation and about 270 HB (27 HRC), with annealed, normalized-and-tempered, quenched-and-tempered (including 32–38 HRC) and stress-relieved conditions on file for sand and investment castings. Elongation is low, machinability and weldability are both scored 40, service is capped near 450 °C, and there is no corrosion resistance. Choose SCCrM1 for easier welding and more ductility. SCCrM3 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F). SCCrM3 has a yield strength of 720 MPa (104 ksi) and a tensile strength of 900 MPa (131 ksi) — stronger than 82% of steel grades. Elongation at break is 9% and the elastic modulus is 205 GPa (29.7 Msi).
What is SCCrM3 used for?
- Heavy machinery frames
- High-load gear blanks
- Structural pressure castings
Advantages
- Low embodied carbon — 1.9 kg CO₂/kg, better than 92% of steel grades
- High service temperature — 450°C (842 °F), better than 86% of steel grades
- High strength — 720 MPa (104 ksi), better than 82% of steel grades
Limitations
- Limited formability — 10/100, worse than 95% of steel grades
- Limited ductility — 9%, worse than 93% of steel grades
- Difficult to machine — 40/100, worse than 77% of steel grades
SCCrM3 properties
Typical room-temperature values for SCCrM3-QT; bars are the position among steel grades.
Physical3
SCCrM3 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical16
SCCrM3 has a yield strength of 720 MPa (104 ksi) and a tensile strength of 900 MPa (131 ksi) — stronger than 82% of steel grades. Elongation at break is 9% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
SCCrM3 is rated for continuous service to 450°C (842 °F). It conducts heat at 42 W/m·K (24.3 BTU/hr·ft·°F), worse than 56% of steel grades. Thermal expansion is 12.3 µm/m·K (6.83 µin/in·°F).
Electrical2
SCCrM3 has an electrical resistivity of 2.2×10⁻⁷ Ω·m.
Chemical & Environmental2
Corrosion resistance is not recommended (13/100), better than 66% of steel grades.
Sustainability4
Producing a kilogram of SCCrM3 takes about 25 MJ of energy and emits 1.9 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 80%.
Manufacturability7
SCCrM3's machinability is fair (40/100, worse than 77% of 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 steel family
Yield strength against density for every steel grade FabDigit runs. SCCrM3 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with SCCrM3
Is SCCrM3 easy to machine?
Rough machine in the annealed or stress-relieved state and finish after Q&T; use rigid setups, coated carbide, moderate speeds and watch for hard spots/scale near feeders.
Can SCCrM3 be welded?
Weldable with matching low-alloy Cr-Mo filler using 200–300 °C preheat, low-hydrogen practice and post-weld tempering/stress relief below the original tempering temperature.
Can SCCrM3 be formed, bent or molded?
Sand or investment cast; needs generous feeding and chills against shrinkage, plus normalizing or Q&T to break up as-cast dendritic structure.
SCCrM3 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 |
|---|---|---|
| Chigher carbon than SCCrM1 to reach the 880 MPa class; verify against current JIS G5111 edition | 0.3 – 0.4 | 0.35 |
| Si | ≤ 0.8 | 0.45 |
| Mn | ≤ 0.9 | 0.7 |
| P | ≤ 0.04 | 0.02 |
| S | ≤ 0.04 | 0.02 |
| Cr | 0.8 – 1.5 | 1.1 |
| Mo | 0.15 – 0.35 | 0.25 |
| Fe | balance |
What surface finishes work on SCCrM3?
No inherent corrosion resistance — shot blast then paint, zinc-rich primer, phosphate/oil or hard chrome; nitriding or induction hardening can be used for local wear surfaces.
Surface treatments FabDigit runs on 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).
Organic Coating
Black / Phosphate
Thermal Spray
How much does SCCrM3 cost?
SCCrM3 is a standard-cost steel ($$), cheaper than about 71% 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.
SCCrM3 — frequently asked
What is SCCrM3 used for?
SCCrM3 is typically used for heavy machinery frames, high-load gear blanks and structural pressure castings. In short: highest-strength JIS Cr-Mo casting; strength over ductility; needs strict preheat control.
What is the yield strength of SCCrM3?
SCCrM3 has a typical yield strength of 720 MPa (104 ksi) and a tensile strength of 900 MPa (131 ksi) — stronger than 82% of steel grades. Strength varies by condition: see the 5 listed tempers.
Is SCCrM3 easy to machine?
Not especially — machinability is rated fair (40/100, worse than 77% of steel grades). Rough machine in the annealed or stress-relieved state and finish after Q&T; use rigid setups, coated carbide, moderate speeds and watch for hard spots/scale near feeders.
Can SCCrM3 be welded?
With care — weldability is rated fair (40/100). Weldable with matching low-alloy Cr-Mo filler using 200–300 °C preheat, low-hydrogen practice and post-weld tempering/stress relief below the original tempering temperature.
What surface finishes work on SCCrM3?
No inherent corrosion resistance — shot blast then paint, zinc-rich primer, phosphate/oil or hard chrome; nitriding or induction hardening can be used for local wear surfaces.
Can SCCrM3 be formed, bent or molded?
Sand or investment cast; needs generous feeding and chills against shrinkage, plus normalizing or Q&T to break up as-cast dendritic structure.
What is the maximum service temperature of SCCrM3?
SCCrM3 is rated for continuous use to about 450°C (842 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between SCCrM3-QT and SCCrM3-A?
QT is the default condition — standard supply condition meeting the JIS G5111 SCCrM3 minima (≈685 MPa PS / 880 MPa TS); the default choice for high-load structural and pressure-bearing castings. A: pick for maximum machinability and dimensional stability before final heat treatment or when strength is not critical. Yield strength is 720 MPa in QT versus 400 MPa in A.
How much does SCCrM3 cost?
SCCrM3 is a standard-cost steel ($$), cheaper than about 71% 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
- JIS G5111 — Steel castings for structural purposes (low-alloy) — Japanese Standards Association (1991)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys (cast low-alloy steels) — ASM International (1990)
- Steel Castings Handbook, 6th ed. — Steel Founders' Society of America (1995)
- ASM Handbook Vol.19 — Fatigue and Fracture — ASM International (1996)
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.