Steel SC480-QT (Quenched and tempered)
Heat-treated state
JIS G5101
Optional upgrade for highly stressed castings (gears, links, valve bodies) where 600–700 MPa tensile and better toughness are needed; section-size limited by hardenability.
Values for the QT condition
Other SC480 tempers and conditions
SC480 is listed in 6 conditions; see the grade overview at SC480.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
As fabricated | Rarely supplied to JIS G5101 (which requires heat treatment); only for non-critical parts where as-cast strength is acceptable. | 260 | 500 | 12 | 170 HB | 9 % IACS |
Solution annealed | Pick when maximum machinability, dimensional stability and low residual stress matter more than strength. | 260 | 495 | 21 | 150 HB | — |
Stress relieved | Sub-critical 580–650 °C soak used after weld repair or heavy machining; mechanical properties essentially those of the prior N or NT condition. | 285 | 515 | 19 | 158 HB | 9 % IACS |
NDefault Normalized | Standard delivery condition: refines the as-cast dendritic structure and reliably meets the 480 MPa / 13 % JIS minimums. | 290 | 520 | 18 | 160 HB | — |
Normalized and tempered | Best all-round condition for machine frames and pressure parts: same strength as normalized with lower residual stress and better toughness. | 310 | 540 | 20 | 165 HB | — |
QTThis page Quenched and tempered | Optional upgrade for highly stressed castings (gears, links, valve bodies) where 600–700 MPa tensile and better toughness are needed; section-size limited by hardenability. | 430 | 650 | 18 | 20 HRC | — |
What is SC480-QT?
SC480-QT is SC480 heat treated to QT — optional upgrade for highly stressed castings (gears, links, valve bodies) where 600–700 MPa tensile and better toughness are needed; section-size limited by hardenability. SC480-QT has a yield strength of 430 MPa (62.4 ksi) and a tensile strength of 650 MPa (94.3 ksi) — weaker than 51% of steel grades. Elongation at break is 18% and the elastic modulus is 205 GPa (29.7 Msi). SC480-QT has a density of 7.82 g/cm³ (0.283 lb/in³), lighter than 82% of steel grades. It melts at 1,425°C (2,597 °F). N is the default condition FabDigit quotes; QT is available on request or by drawing note.
Advantages
- Low embodied carbon — 1.9 kg CO₂/kg, better than 92% of steel grades
- Conducts heat well — 48 W/m·K (27.7 BTU/hr·ft·°F), better than 79% of steel grades
Limitations
- Limited formability — 15/100, worse than 87% of steel grades
SC480-QT properties
Typical room-temperature values for SC480-QT; 14 are specific to this condition. Other listed values are SC480 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
SC480-QT has a density of 7.82 g/cm³ (0.283 lb/in³), lighter than 82% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical16
SC480-QT has a yield strength of 430 MPa (62.4 ksi) and a tensile strength of 650 MPa (94.3 ksi) — weaker than 51% of steel grades. Elongation at break is 18% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
SC480-QT is rated for continuous service to 425°C (797 °F). It conducts heat at 48 W/m·K (27.7 BTU/hr·ft·°F), better than 79% of steel grades. Thermal expansion is 11.7 µm/m·K (6.5 µin/in·°F).
Electrical3
SC480-QT conducts electricity at 9 % IACS, better than 71% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 86% of steel grades.
Sustainability4
Producing a kilogram of SC480-QT takes about 25 MJ of energy and emits 1.9 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 85%.
Manufacturability7
SC480-QT's machinability is fair (48/100, worse than 57% of steel grades); weldability fair (45/100); formability poor (15/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with SC480-QT
Is SC480 easy to machine?
Machines like normalized 1045: carbide inserts, 120–180 m/min, watch for hard scale, sand inclusions and shrinkage porosity near risers.
Can SC480 be welded?
Weldable with low-hydrogen E7018/ER70S-6 but CE ≈ 0.55 — preheat 150–250 °C, control interpass, and stress relieve 580–650 °C after repair.
Can SC480 be formed, bent or molded?
Sand or shell cast with generous risering and chills; long freezing range means centreline shrinkage in heavy sections — normalize after shakeout.
What surface finishes work on SC480?
No corrosion resistance of its own: shot blast then prime/paint, zinc-rich coat or phosphate; can be flame or induction hardened locally on wear faces.
SC480 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 |
|---|---|---|
| Cnot limited by JIS G5101; typical foundry aim to reach 480 MPa | 0.35 – 0.5 | 0.45 |
| Sitypical foundry range | 0.2 – 0.6 | 0.4 |
| Mntypical foundry range | 0.5 – 1 | 0.75 |
| PJIS G5101 limit | ≤ 0.04 | 0.03 |
| SJIS G5101 limit | ≤ 0.04 | 0.03 |
| Fe | balance | — |
SC480-QT — frequently asked
What is SC480-QT used for?
SC480-QT is typically used for heavy machinery parts, high-pressure valve bodies and crane and construction equipment castings. In short: strongest general SC grade; needs preheat for welding; locally hardenable wear faces.
What is the yield strength of SC480-QT?
SC480-QT has a typical yield strength of 430 MPa (62.4 ksi) and a tensile strength of 650 MPa (94.3 ksi) — weaker than 51% of steel grades. Strength varies by condition: see the 6 listed tempers.
Is SC480-QT easy to machine?
Reasonably — machinability is rated fair (48/100, worse than 57% of steel grades). Machines like normalized 1045: carbide inserts, 120–180 m/min, watch for hard scale, sand inclusions and shrinkage porosity near risers.
Can SC480-QT be welded?
With care — weldability is rated fair (45/100). Weldable with low-hydrogen E7018/ER70S-6 but CE ≈ 0.55 — preheat 150–250 °C, control interpass, and stress relieve 580–650 °C after repair.
What surface finishes work on SC480-QT?
No corrosion resistance of its own: shot blast then prime/paint, zinc-rich coat or phosphate; can be flame or induction hardened locally on wear faces.
Can SC480-QT be formed, bent or molded?
Sand or shell cast with generous risering and chills; long freezing range means centreline shrinkage in heavy sections — normalize after shakeout.
What is the maximum service temperature of SC480-QT?
SC480-QT 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 SC480-N and SC480-QT?
N is the default condition — standard delivery condition: refines the as-cast dendritic structure and reliably meets the 480 MPa / 13 % JIS minimums. QT: optional upgrade for highly stressed castings (gears, links, valve bodies) where 600–700 MPa tensile and better toughness are needed; section-size limited by hardenability. Yield strength is 290 MPa in N versus 430 MPa in QT.
Sources
- JIS G5101 — Carbon steel castings — JISC (1991)
- GB/T 11352 — (ZG310-570 comparison) — SAC (2009)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels — ASM International (1990)
- Steel Castings Handbook — Steel Founders' Society of America (1995)
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.