Steel 5015 CARB-RQT
Heat-treated state
AISI/SAE 5015 · UNS G50150
Use when maximum core toughness and minimum distortion/retained austenite are required.
Values for the CARB-RQT condition
Other 5015 tempers and conditions
5015 is listed in 7 conditions; see the grade overview at 5015.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Hot rolled | Lowest-cost mill condition for parts that will be fully machined and then carburized. | 275 | 440 | 30 | 126 HB | 9.5 % IACS |
ADefault Solution annealed | Softest, most machinable and most formable condition; standard supply state before carburizing. | 285 | 415 | 32 | 121 HB | — |
Normalized | Uniform fine-grain structure for stable machining and predictable carburizing response. | 315 | 470 | 28 | 137 HB | 9.5 % IACS |
Cold drawn | Choose for close tolerance, straight bar and higher as-supplied strength on screw-machine parts. | 450 | 525 | 15 | 149 HB | 9.5 % IACS |
Quenched and tempered | For thin sections used without a case, where moderate strength plus good toughness is enough. | 470 | 640 | 20 | 14 HRC | 9.3 % IACS |
CARB-RQTThis page Carburized, reheat quenched and tempered (refined core) | Use when maximum core toughness and minimum distortion/retained austenite are required. | 520 | 720 | 16 | 59 HRC | 9 % IACS |
Carburized, direct quenched and low-temperature tempered (case 58–62 HRC) | Standard service condition: hard wear-resistant case over a tough low-carbon martensitic core. | 550 | 760 | 13 | 60 HRC | — |
What is 5015 CARB-RQT?
5015 CARB-RQT is 5015 heat treated to CARB-RQT — use when maximum core toughness and minimum distortion/retained austenite are required. 5015 CARB-RQT has a yield strength of 520 MPa (75.4 ksi) and a tensile strength of 720 MPa (104 ksi) — stronger than 67% of steel grades. Elongation at break is 16% and the elastic modulus is 205 GPa (29.7 Msi). 5015 CARB-RQT 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). A is the default condition FabDigit quotes; CARB-RQT is available on request or by drawing note.
Limitations
- Limited formability — 5/100, worse than 99% of steel grades
- Limited service temperature — 180°C (356 °F), worse than 98% of steel grades
- Difficult to machine — 18/100, worse than 97% of steel grades
- Difficult to weld — 20/100, worse than 84% of steel grades
5015 CARB-RQT properties
Typical room-temperature values for 5015 CARB-RQT; 22 are specific to this condition. Other listed values are 5015 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
5015 CARB-RQT 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).
Mechanical13
5015 CARB-RQT has a yield strength of 520 MPa (75.4 ksi) and a tensile strength of 720 MPa (104 ksi) — stronger than 67% of steel grades. Elongation at break is 16% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
5015 CARB-RQT is rated for continuous service to 180°C (356 °F). It conducts heat at 42 W/m·K (24.3 BTU/hr·ft·°F), worse than 56% of steel grades. Thermal expansion is 11.9 µm/m·K (6.61 µin/in·°F).
Electrical3
5015 CARB-RQT conducts electricity at 9 % IACS, better than 71% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of 5015 CARB-RQT takes about 30 MJ of energy and emits 2.2 kg of CO₂ — more than 56% of steel grades. Typical recycled content is 30%.
Manufacturability7
5015 CARB-RQT's machinability is poor (18/100, worse than 97% of steel grades); weldability poor (20/100); formability not recommended (5/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 5015 CARB-RQT
Is 5015 easy to machine?
Machine in the annealed or normalized condition (~60 % of AISI 1212); soft low-carbon structure is gummy, so use sharp positive-rake tooling, high speed and generous coolant, and finish-grind after carburizing.
Can 5015 be welded?
Good weldability before carburizing (CE ≈ 0.30) by GMAW/GTAW with low-hydrogen consumables; never weld a carburized surface — the high-carbon case will crack.
Can 5015 be formed, bent or molded?
Cold heading, bending and light drawing are practical in the annealed state; hot work at 1050–1200 °C, finish above 850 °C, then normalize.
What surface finishes work on 5015?
No natural corrosion resistance — apply black oxide, manganese phosphate + oil, zinc or zinc-nickel plating (bake to avoid hydrogen embrittlement); case-hardened surfaces polish and grind well.
5015 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 |
|---|---|---|
| Cheat analysis, SAE J404 | 0.12 – 0.17 | 0.15 |
| Mn | 0.3 – 0.5 | 0.4 |
| Si | 0.15 – 0.35 | 0.25 |
| Cr | 0.3 – 0.5 | 0.4 |
| P | ≤ 0.04 | — |
| S | ≤ 0.04 | — |
| Fe | balance | — |
5015 CARB-RQT — frequently asked
What is 5015 CARB-RQT used for?
5015 CARB-RQT is typically used for pins, small gears and cam followers. In short: entry-level carburizing steel; most formable in family; light-duty hard case.
What is the yield strength of 5015 CARB-RQT?
5015 CARB-RQT has a typical yield strength of 520 MPa (75.4 ksi) and a tensile strength of 720 MPa (104 ksi) — stronger than 67% of steel grades. Strength varies by condition: see the 7 listed tempers.
Is 5015 CARB-RQT easy to machine?
Not especially — machinability is rated poor (18/100, worse than 97% of steel grades). Machine in the annealed or normalized condition (~60 % of AISI 1212); soft low-carbon structure is gummy, so use sharp positive-rake tooling, high speed and generous coolant, and finish-grind after carburizing.
Can 5015 CARB-RQT be welded?
Not readily — weldability is rated poor (20/100). Good weldability before carburizing (CE ≈ 0.30) by GMAW/GTAW with low-hydrogen consumables; never weld a carburized surface — the high-carbon case will crack.
What surface finishes work on 5015 CARB-RQT?
No natural corrosion resistance — apply black oxide, manganese phosphate + oil, zinc or zinc-nickel plating (bake to avoid hydrogen embrittlement); case-hardened surfaces polish and grind well.
Can 5015 CARB-RQT be formed, bent or molded?
Cold heading, bending and light drawing are practical in the annealed state; hot work at 1050–1200 °C, finish above 850 °C, then normalize.
What is the maximum service temperature of 5015 CARB-RQT?
5015 CARB-RQT 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 5015-A and 5015 QT-CORE?
A is the default condition — softest, most machinable and most formable condition; standard supply state before carburizing. QT-CORE: for thin sections used without a case, where moderate strength plus good toughness is enough. Yield strength is 285 MPa in A versus 470 MPa in QT-CORE.
Sources
- SAE J404 — Chemical Compositions of SAE Alloy Steels — SAE International (2021)
- SAE J1268 — Hardenability Bands for Carbon and Alloy H Steels — SAE International (2019)
- ASTM A29/A29M — Steel Bars, Carbon and Alloy, Hot-Wrought — ASTM International (2020)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.4A — Steel Heat Treating Fundamentals and Processes (carburizing) — ASM International (2013)
- GB/T 3077 (15Cr equivalent) — SAC (2015)
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.