Steel SCCrM3-A (Solution annealed)
Temper
Pick for maximum machinability and dimensional stability before final heat treatment or when strength is not critical.
Values for the A condition
Other SCCrM3 tempers and conditions
SCCrM3 is listed in 5 conditions; see the grade overview at SCCrM3.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AThis page 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-A?
SCCrM3-A is SCCrM3 in the A temper — pick for maximum machinability and dimensional stability before final heat treatment or when strength is not critical. SCCrM3-A has a yield strength of 400 MPa (58 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 60% of steel grades. Elongation at break is 20% and the elastic modulus is 205 GPa (29.7 Msi). SCCrM3-A 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). QT is the default condition FabDigit quotes; A is available on request or by drawing note.
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
Limitations
- Limited formability — 10/100, worse than 95% of steel grades
SCCrM3-A properties
Typical room-temperature values for SCCrM3-A; 11 are specific to this condition. Other listed values are SCCrM3 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
SCCrM3-A 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-A has a yield strength of 400 MPa (58 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 60% of steel grades. Elongation at break is 20% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
SCCrM3-A 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-A 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-A 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-A's machinability is good (55/100, better than 62% of steel grades); weldability fair (50/100); formability not recommended (10/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with SCCrM3-A
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.
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.
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 | — |
SCCrM3-A — frequently asked
What is SCCrM3-A used for?
SCCrM3-A 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-A?
SCCrM3-A has a typical yield strength of 400 MPa (58 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 60% of steel grades. Strength varies by condition: see the 5 listed tempers.
Is SCCrM3-A easy to machine?
Reasonably — machinability is rated good (55/100, better than 62% 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-A be welded?
With care — weldability is rated fair (50/100). 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-A?
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-A 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-A?
SCCrM3-A 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.
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. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.