Steel Y30 QT24-28HRC
Heat-treated state
GB Y30
Choose for moderately loaded machined shafts and fittings that still need reasonable toughness.
Values for the QT24-28HRC condition
Other Y30 tempers and conditions
Y30 is listed in 8 conditions; see the grade overview at Y30.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution annealed | Softest condition; choose when maximum dimensional stability or cold forming after machining is needed. | 280 | 500 | 23 | 160 HB | — |
Hot rolled | Lowest-cost stock for larger diameters that will be fully machined or heat treated later. | 320 | 545 | 17 | 170 HB | — |
Normalized | Uniform fine pearlitic structure for consistent machining response and better toughness than as-rolled heavy sections. | 340 | 570 | 19 | 180 HB | — |
Cold drawn, stress relieved | Pick when slender turned or milled parts must stay straight after asymmetric metal removal. | 490 | 620 | 13 | 190 HB | — |
CDDefault Cold drawn | Standard stocked condition: tight tolerance, bright surface and higher yield strength for automatic-lathe production parts. | 540 | 640 | 10 | 197 HB | — |
Induction hardened | Used on finished Y30 shafts/journals needing a hard wear surface over a tough core. | 560 | 700 | 10 | 54 HRC | 8.8 % IACS |
QT24-28HRCThis page quenched and tempered, medium strength | Choose for moderately loaded machined shafts and fittings that still need reasonable toughness. | 700 | 860 | 15 | 26 HRC | — |
quenched and tempered, high strength | Highest practical through-hardened strength for Y30; use where wear and load beat the need for impact toughness. | 830 | 1,000 | 12 | 32 HRC | — |
What is Y30 QT24-28HRC?
Y30 QT24-28HRC is Y30 heat treated to QT24-28HRC — choose for moderately loaded machined shafts and fittings that still need reasonable toughness. Y30 QT24-28HRC has a yield strength of 700 MPa (102 ksi) and a tensile strength of 860 MPa (125 ksi) — stronger than 81% of steel grades. Elongation at break is 15% and the elastic modulus is 205 GPa (29.7 Msi). Y30 QT24-28HRC 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). CD is the default condition FabDigit quotes; QT24-28HRC is available on request or by drawing note.
Advantages
- Low embodied carbon — 1.9 kg CO₂/kg, better than 92% of steel grades
- High strength — 700 MPa (102 ksi), better than 81% of steel grades
- High electrical conductivity — 9.6 % IACS, better than 78% of steel grades
Limitations
- Limited formability — 15/100, worse than 87% of steel grades
- Low fracture toughness — 50 MPa·√m (45.5 ksi·√in), worse than 86% of steel grades
- Difficult to weld — 25/100, worse than 77% of steel grades
Y30 QT24-28HRC properties
Typical room-temperature values for Y30 QT24-28HRC; 13 are specific to this condition. Other listed values are Y30 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
Y30 QT24-28HRC 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
Y30 QT24-28HRC has a yield strength of 700 MPa (102 ksi) and a tensile strength of 860 MPa (125 ksi) — stronger than 81% of steel grades. Elongation at break is 15% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
Y30 QT24-28HRC is rated for continuous service to 400°C (752 °F). It conducts heat at 47 W/m·K (27.2 BTU/hr·ft·°F), better than 75% of steel grades. Thermal expansion is 11.7 µm/m·K (6.5 µin/in·°F).
Electrical3
Y30 QT24-28HRC conducts electricity at 9.6 % IACS, better than 78% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (11/100), worse than 73% of steel grades.
Sustainability4
Producing a kilogram of Y30 QT24-28HRC takes about 25 MJ of energy and emits 1.9 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 30%.
Manufacturability7
Y30 QT24-28HRC's machinability is good (58/100, better than 75% of steel grades); weldability poor (25/100); formability poor (15/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Y30 QT24-28HRC
Is Y30 easy to machine?
Excellent for high-speed automatic turning — MnS inclusions give short chips and clean threads; run generous speeds with sharp carbide and coolant, and expect ~75 % of AISI 1212 rate.
Can Y30 be welded?
Not recommended for structural welds; high sulfur plus medium carbon promotes hot cracking and porosity — if unavoidable, preheat 150–250 °C, use low-hydrogen filler and post-weld stress relieve.
Can Y30 be formed, bent or molded?
Limited cold formability and poor transverse ductility; do bending/heading with generous radii or work hot at 1050–1200 °C, avoiding finishing below ~850 °C.
What surface finishes work on Y30?
Takes zinc/nickel plating, black oxide, phosphating and paint well after degreasing; sulfide inclusions can leave micro-pits or streaks on mirror-polished or hard-chromed surfaces.
Y30 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 | 0.27 – 0.35 | 0.31 |
| Si | 0.15 – 0.35 | 0.25 |
| Mncombines with S to form free-cutting MnS | 0.7 – 1 | 0.85 |
| Sintentional free-machining addition | 0.08 – 0.2 | 0.14 |
| P | ≤ 0.06 | 0.03 |
| Crresidual | ≤ 0.15 | — |
| Niresidual | ≤ 0.25 | — |
| Curesidual | ≤ 0.25 | — |
| Fe | balance | — |
Y30 QT24-28HRC — frequently asked
What is Y30 QT24-28HRC used for?
Y30 QT24-28HRC is typically used for shafts, bolts and studs. In short: stronger than Y12/Y15 grades; heat-treatable to 34 HRC; free-cutting 1132 equivalent.
What is the yield strength of Y30 QT24-28HRC?
Y30 QT24-28HRC has a typical yield strength of 700 MPa (102 ksi) and a tensile strength of 860 MPa (125 ksi) — stronger than 81% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is Y30 QT24-28HRC easy to machine?
Reasonably — machinability is rated good (58/100, better than 75% of steel grades). Excellent for high-speed automatic turning — MnS inclusions give short chips and clean threads; run generous speeds with sharp carbide and coolant, and expect ~75 % of AISI 1212 rate.
Can Y30 QT24-28HRC be welded?
Not readily — weldability is rated poor (25/100). Not recommended for structural welds; high sulfur plus medium carbon promotes hot cracking and porosity — if unavoidable, preheat 150–250 °C, use low-hydrogen filler and post-weld stress relieve.
What surface finishes work on Y30 QT24-28HRC?
Takes zinc/nickel plating, black oxide, phosphating and paint well after degreasing; sulfide inclusions can leave micro-pits or streaks on mirror-polished or hard-chromed surfaces.
Can Y30 QT24-28HRC be formed, bent or molded?
Limited cold formability and poor transverse ductility; do bending/heading with generous radii or work hot at 1050–1200 °C, avoiding finishing below ~850 °C.
What is the maximum service temperature of Y30 QT24-28HRC?
Y30 QT24-28HRC 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 Y30-CD and Y30-A?
CD is the default condition — standard stocked condition: tight tolerance, bright surface and higher yield strength for automatic-lathe production parts. A: softest condition; choose when maximum dimensional stability or cold forming after machining is needed. Yield strength is 540 MPa in CD versus 280 MPa in A.
Sources
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.16 — Machining — ASM International (1989)
- SAE J403 / AISI 1132 resulfurized carbon steel composition — SAE International (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.