Steel 1524 CARB-QT
Heat-treated state
AISI/SAE 1524 · UNS G15240
CARB-QT = carburized, quenched & low-temper
Pick when a hard wear surface (≈0.5–1.2 mm case, 55–62 HRC) is needed over a tough medium-strength core on light-duty gears and pins.
Values for the CARB-QT condition
Other 1524 tempers and conditions
1524 is listed in 5 conditions; see the grade overview at 1524.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution annealed | Softest, most ductile condition for deep machining, cold forming or as a pre-carburizing structure. | 275 | 470 | 26 | 137 HB | — |
HRDefault Hot rolled | Cheapest stock condition for forged, machined or carburized parts where tolerance and surface finish are not critical. | 305 | 510 | 20 | 149 HB | — |
Normalized | Use to refine forged or hot-rolled grain, even out properties and improve toughness before machining or case hardening. | 315 | 530 | 22 | 156 HB | — |
Cold drawn | Choose for straight, close-tolerance bright bar with higher yield strength and better as-machined finish. | 505 | 585 | 15 | 170 HB | — |
CARB-QTThis page Carburized, quenched & low-temper | Pick when a hard wear surface (≈0.5–1.2 mm case, 55–62 HRC) is needed over a tough medium-strength core on light-duty gears and pins. | 520 | 760 | 14 | 59 HRC | — |
What is 1524 CARB-QT?
1524 CARB-QT is 1524 heat treated to CARB-QT — pick when a hard wear surface (≈0.5–1.2 mm case, 55–62 HRC) is needed over a tough medium-strength core on light-duty gears and pins. 1524 CARB-QT has a yield strength of 520 MPa (75.4 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 67% of steel grades. Elongation at break is 14% and the elastic modulus is 200 GPa (29 Msi). 1524 CARB-QT 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). HR is the default condition FabDigit quotes; CARB-QT is available on request or by drawing note.
Advantages
- Conducts heat well — 51.9 W/m·K (30 BTU/hr·ft·°F), better than 96% of steel grades
- High electrical conductivity — 10.8 % IACS, better than 94% of steel grades
- Low embodied carbon — 1.9 kg CO₂/kg, better than 92% of steel grades
Limitations
- Limited service temperature — 180°C (356 °F), worse than 98% of steel grades
- Difficult to machine — 20/100, worse than 97% of steel grades
- Limited formability — 10/100, worse than 95% of steel grades
- Hard to polish — 45/100, worse than 84% of steel grades
- Difficult to weld — 25/100, worse than 77% of steel grades
1524 CARB-QT properties
Typical room-temperature values for 1524 CARB-QT; 14 are specific to this condition. Other listed values are 1524 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
1524 CARB-QT 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
1524 CARB-QT has a yield strength of 520 MPa (75.4 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 67% of steel grades. Elongation at break is 14% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
1524 CARB-QT is rated for continuous service to 180°C (356 °F). It conducts heat at 51.9 W/m·K (30 BTU/hr·ft·°F), better than 96% of steel grades. Thermal expansion is 11.7 µm/m·K (6.5 µin/in·°F).
Electrical3
1524 CARB-QT conducts electricity at 10.8 % IACS, better than 94% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 86% of steel grades.
Sustainability4
Producing a kilogram of 1524 CARB-QT takes about 24 MJ of energy and emits 1.9 kg of CO₂ — less than 97% of steel grades. Typical recycled content is 30%.
Manufacturability7
1524 CARB-QT's machinability is poor (20/100, worse than 97% of steel grades); weldability poor (25/100); formability not recommended (10/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 1524 CARB-QT
Is 1524 easy to machine?
Machines like a gummy low-carbon steel — use sharp positive-rake tooling, good coolant and chip breakers; normalizing or cold drawing improves chip control over annealed stock.
Can 1524 be welded?
Readily welded by SMAW/GMAW with E70-class filler; carbon equivalent near 0.45–0.50 means 100–150 °C preheat for sections over ~25 mm and no welding after carburizing.
Can 1524 be formed, bent or molded?
Good hot forgeability at 1100–1230 °C; cold bending is fine in annealed/hot-rolled bar but cold-drawn bar has limited remaining ductility.
What surface finishes work on 1524?
No inherent corrosion resistance — specify oil, phosphate-and-oil, zinc plate, black oxide or paint; takes decorative plating well after fine grinding.
1524 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 |
|---|---|---|
| C | 0.19 – 0.25 | 0.22 |
| Mnhigh-Mn carbon steel series | 1.35 – 1.65 | 1.5 |
| Pmax, SAE J403 bar | ≤ 0.03 | — |
| Smax, SAE J403 bar | ≤ 0.05 | — |
| Sitypical for killed steel; not always specified | 0.15 – 0.35 | 0.25 |
| Fe | balance | — |
1524 CARB-QT — frequently asked
What is 1524 CARB-QT used for?
1524 CARB-QT is typically used for low-load gears, wear pins and dowels, bushings and sleeves, chain sprockets, levers and linkage parts and studs and shoulder bolts. In short: cheapest carburizing option; best weldability in family; light-duty wear parts.
What is the yield strength of 1524 CARB-QT?
1524 CARB-QT has a typical yield strength of 520 MPa (75.4 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 67% of steel grades. Strength varies by condition: see the 5 listed tempers.
Is 1524 CARB-QT easy to machine?
Not especially — machinability is rated poor (20/100, worse than 97% of steel grades). Machines like a gummy low-carbon steel — use sharp positive-rake tooling, good coolant and chip breakers; normalizing or cold drawing improves chip control over annealed stock.
Can 1524 CARB-QT be welded?
Not readily — weldability is rated poor (25/100). Readily welded by SMAW/GMAW with E70-class filler; carbon equivalent near 0.45–0.50 means 100–150 °C preheat for sections over ~25 mm and no welding after carburizing.
What surface finishes work on 1524 CARB-QT?
No inherent corrosion resistance — specify oil, phosphate-and-oil, zinc plate, black oxide or paint; takes decorative plating well after fine grinding.
Can 1524 CARB-QT be formed, bent or molded?
Good hot forgeability at 1100–1230 °C; cold bending is fine in annealed/hot-rolled bar but cold-drawn bar has limited remaining ductility.
What is the maximum service temperature of 1524 CARB-QT?
1524 CARB-QT is rated for continuous use to about 180°C (356 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 1524-HR and 1524 CARB-QT?
HR is the default condition — cheapest stock condition for forged, machined or carburized parts where tolerance and surface finish are not critical. CARB-QT: pick when a hard wear surface (≈0.5–1.2 mm case, 55–62 HRC) is needed over a tough medium-strength core on light-duty gears and pins. Yield strength is 305 MPa in HR versus 520 MPa in CARB-QT.
Sources
- SAE J403 — Chemical Compositions of SAE Carbon Steels — SAE International (2014)
- ASTM A29/A29M — Steel Bars, Carbon and Alloy, Hot-Wrought, General Requirements — ASTM (2020)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.4 — Heat Treating (carburizing of carbon steels) — ASM International (1991)
- ASM Handbook Vol.16 — Machining — ASM International (1989)
- MatWeb material property data, AISI 1524 hot rolled / cold drawn — MatWeb LLC (2024)
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.