Steel SCMn1 Q+T
Heat-treated state
JIS SCMn1
Q+T = quenched and tempered
Choose when higher yield strength and section toughness are needed; limited by hardenability to moderate wall thickness.
Values for the Q+T condition
Other SCMn1 tempers and conditions
SCMn1 is listed in 4 conditions; see the grade overview at SCMn1.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution annealed | Softest condition, used for heavy rough machining or as an intermediate state before final N+T / Q+T. | 300 | 520 | 24 | 150 HB | — |
As fabricated | Non-standard shipping state for non-critical or later-heat-treated parts; JIS G5111 properties only apply after heat treatment. | 310 | 540 | 14 | 170 HB | 8 % IACS |
N+TDefault Normalized and tempered | Standard JIS G5111 delivery condition: best balance of 540 MPa-class strength, ductility and cost for general structural castings. | 380 | 580 | 21 | 175 HB | — |
Q+TThis page Quenched and tempered | Choose when higher yield strength and section toughness are needed; limited by hardenability to moderate wall thickness. | 500 | 680 | 18 | 18 HRC | — |
What is SCMn1 Q+T?
SCMn1 Q+T is SCMn1 heat treated to Q+T — choose when higher yield strength and section toughness are needed; limited by hardenability to moderate wall thickness. SCMn1 Q+T has a yield strength of 500 MPa (72.5 ksi) and a tensile strength of 680 MPa (98.6 ksi) — stronger than 63% of steel grades. Elongation at break is 18% and the elastic modulus is 205 GPa (29.7 Msi). SCMn1 Q+T has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F). N+T is the default condition FabDigit quotes; Q+T is available on request or by drawing note.
Limitations
- Limited formability — 20/100, worse than 80% of steel grades
SCMn1 Q+T properties
Typical room-temperature values for SCMn1 Q+T; 13 are specific to this condition. Other listed values are SCMn1 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
SCMn1 Q+T has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical16
SCMn1 Q+T has a yield strength of 500 MPa (72.5 ksi) and a tensile strength of 680 MPa (98.6 ksi) — stronger than 63% of steel grades. Elongation at break is 18% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
SCMn1 Q+T is rated for continuous service to 400°C (752 °F). It conducts heat at 45 W/m·K (26 BTU/hr·ft·°F), better than 66% of steel grades. Thermal expansion is 12.3 µm/m·K (6.83 µin/in·°F).
Electrical3
SCMn1 Q+T conducts electricity at 8 % IACS, better than 55% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of SCMn1 Q+T takes about 26 MJ of energy and emits 2 kg of CO₂ — less than 64% of steel grades. Typical recycled content is 80%.
Manufacturability8
SCMn1 Q+T's machinability is fair (48/100, worse than 57% of steel grades); weldability good (55/100); formability poor (20/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with SCMn1 Q+T
Is SCMn1 easy to machine?
Machines like normalized 1330/ZG20Mn — carbide inserts, moderate speeds; remove the hard cast skin with a heavy first cut to protect edges.
Can SCMn1 be welded?
Good weldability with low-hydrogen SMAW/FCAW or GMAW; CE ≈ 0.5–0.6, so preheat 100–200 °C on heavy sections and stress-relieve or re-normalize after major repair welds.
Can SCMn1 be formed, bent or molded?
Sand or investment cast with generous risering; Mn increases shrinkage and hot-tear sensitivity, so use adequate feeding and controlled cooling, then normalize+temper to break up the as-cast dendritic structure.
What surface finishes work on SCMn1?
No corrosion resistance of its own — shot blast, then prime/paint, zinc-rich coat, hot-dip galvanize or phosphate; hard chrome or nitriding for local wear surfaces.
SCMn1 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 |
|---|---|---|
| CJIS G5111 | 0.2 – 0.3 | 0.25 |
| Si | 0.3 – 0.6 | 0.45 |
| Mnprimary strengthening/hardenability element | 1 – 1.6 | 1.3 |
| P | ≤ 0.04 | 0.02 |
| S | ≤ 0.04 | 0.02 |
| Fe | balance | — |
SCMn1 Q+T — frequently asked
What is SCMn1 Q+T used for?
SCMn1 Q+T is typically used for heavy machine bases, structural brackets and railway castings. In short: most weldable SCMn grade; easy-machining Mn casting; low-cost structural casting.
What is the yield strength of SCMn1 Q+T?
SCMn1 Q+T has a typical yield strength of 500 MPa (72.5 ksi) and a tensile strength of 680 MPa (98.6 ksi) — stronger than 63% of steel grades. Strength varies by condition: see the 4 listed tempers.
Is SCMn1 Q+T easy to machine?
Reasonably — machinability is rated fair (48/100, worse than 57% of steel grades). Machines like normalized 1330/ZG20Mn — carbide inserts, moderate speeds; remove the hard cast skin with a heavy first cut to protect edges.
Can SCMn1 Q+T be welded?
Yes — weldability is rated good (55/100). Good weldability with low-hydrogen SMAW/FCAW or GMAW; CE ≈ 0.5–0.6, so preheat 100–200 °C on heavy sections and stress-relieve or re-normalize after major repair welds.
What surface finishes work on SCMn1 Q+T?
No corrosion resistance of its own — shot blast, then prime/paint, zinc-rich coat, hot-dip galvanize or phosphate; hard chrome or nitriding for local wear surfaces.
Can SCMn1 Q+T be formed, bent or molded?
Sand or investment cast with generous risering; Mn increases shrinkage and hot-tear sensitivity, so use adequate feeding and controlled cooling, then normalize+temper to break up the as-cast dendritic structure.
What is the maximum service temperature of SCMn1 Q+T?
SCMn1 Q+T is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between SCMn1 N+T and SCMn1-A?
N+T is the default condition — standard JIS G5111 delivery condition: best balance of 540 MPa-class strength, ductility and cost for general structural castings. A: softest condition, used for heavy rough machining or as an intermediate state before final N+T / Q+T. Yield strength is 380 MPa in N+T versus 300 MPa in A.
Sources
- JIS G5111 — Steel castings for structural purposes (high tensile / low alloy) — JSA (2019)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels, and High-Performance Alloys (cast steels) — ASM International (1990)
- Steel Castings Handbook, 6th ed. — Steel Founders' Society of America (1995)
- GB/T 14408 / ZG20Mn comparable cast structural steels — SAC (2014)
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.