Steel T10A QT 45-50 HRC
Hardness band
GB T10A · JIS SK105
QT 45-50 HRC = quenched + tempered 400–450 °C
Tough, shock-resistant setting for springs, cold chisels and tool shanks where edge holding is secondary.
Values for the QT 45-50 HRC condition
Other T10A tempers and conditions
T10A is listed in 8 conditions; see the grade overview at T10A.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AnnealedDefault as-supplied soft condition | Standard stocked condition for bar, plate and strip: soft, machinable and ready for the user's own hardening. | 400 | 700 | 22 | 187 HB | 47 W/m·K |
Hot rolled | Cheapest mill condition; harder and less machinable than annealed, usually annealed by the user before machining. | 480 | 850 | 12 | 25 HRC | 9.5 % IACS |
Normalized | Used to break up carbide networks and refine grain before spheroidizing or hardening. | 560 | 1,000 | 10 | 30 HRC | 9.2 % IACS |
Cold drawn | Precision bar, drill rod and strip with tight size and good surface; slightly work-hardened, still hardenable. | 620 | 800 | 10 | 21 HRC | 9.5 % IACS |
QT 45-50 HRCThis page Quenched + tempered 400–450 °C | Tough, shock-resistant setting for springs, cold chisels and tool shanks where edge holding is secondary. | 1,400 | 1,600 | 5 | 48 HRC | — |
Quenched + tempered 300–350 °C | Chosen where some impact loading exists (chisels, shear blades) at the cost of wear resistance. | 1,550 | 1,850 | 2 | 55 HRC | 8.6 % IACS |
Quenched + tempered 200–250 °C | Common working hardness for punches, simple dies and woodworking blades — slightly tougher than fully hard. | — | 2,000 | 1 | 59 HRC | — |
Water/brine quenched 760–790 °C + tempered 150–180 °C | Maximum hardness and wear resistance for files, scrapers, hand-cutting tools; very brittle, thin sections only. | — | 2,200 | 0.5 | 63 HRC | 42 W/m·K |
What is T10A QT 45-50 HRC?
T10A QT 45-50 HRC is T10A heat treated to QT 45-50 HRC — tough, shock-resistant setting for springs, cold chisels and tool shanks where edge holding is secondary. T10A QT 45-50 HRC has a yield strength of 1,400 MPa (203 ksi) and a tensile strength of 1,600 MPa (232 ksi) — stronger than 96% of steel grades. Elongation at break is 5% and the elastic modulus is 207 GPa (30 Msi). T10A QT 45-50 HRC has a density of 7.81 g/cm³ (0.282 lb/in³), lighter than 84% of steel grades. It melts at 1,400°C (2,552 °F). Annealed is the default condition FabDigit quotes; QT 45-50 HRC is available on request or by drawing note.
Advantages
- High strength — 1,400 MPa (203 ksi), better than 96% of steel grades
- Polishes to a fine finish — 70/100, better than 87% of steel grades
- High electrical conductivity — 9.5 % IACS, better than 75% of steel grades
Limitations
- Limited ductility — 5%, worse than 98% of steel grades
- Difficult to machine — 15/100, worse than 98% of steel grades
- Difficult to weld — 15/100, worse than 91% of steel grades
T10A QT 45-50 HRC properties
Typical room-temperature values for T10A QT 45-50 HRC; 11 are specific to this condition. Other listed values are T10A reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
T10A QT 45-50 HRC has a density of 7.81 g/cm³ (0.282 lb/in³), lighter than 84% of steel grades. It melts at 1,400°C (2,552 °F).
Mechanical15
T10A QT 45-50 HRC has a yield strength of 1,400 MPa (203 ksi) and a tensile strength of 1,600 MPa (232 ksi) — stronger than 96% of steel grades. Elongation at break is 5% and the elastic modulus is 207 GPa (30 Msi).
Thermal6
T10A QT 45-50 HRC is rated for continuous service to 350°C (662 °F). It conducts heat at 47 W/m·K (27.2 BTU/hr·ft·°F), better than 75% of steel grades. Thermal expansion is 11.5 µm/m·K (6.39 µin/in·°F).
Electrical3
T10A QT 45-50 HRC conducts electricity at 9.5 % IACS, better than 75% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 86% of steel grades.
Sustainability4
Producing a kilogram of T10A QT 45-50 HRC takes about 30 MJ of energy and emits 2.3 kg of CO₂ — more than 56% of steel grades. Typical recycled content is 30%.
Manufacturability7
T10A QT 45-50 HRC's machinability is poor (15/100, worse than 98% of steel grades); weldability poor (15/100); formability fair (40/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with T10A QT 45-50 HRC
Is T10A easy to machine?
Machine only in the spheroidize-annealed state (~187 HB, ~65 % of AISI 1212); after hardening only grinding or EDM is practical.
Can T10A be welded?
Essentially unweldable for tool duty — high carbon causes hard, cracking-prone HAZ; if unavoidable preheat 250–300 °C and post-weld anneal immediately.
Can T10A be formed, bent or molded?
Annealed strip bends and blanks acceptably with generous radii; hot forge 1050–850 °C then slow cool/anneal, never forge below 800 °C.
What surface finishes work on T10A?
Takes a fine polish when hardened; protect with oil, black oxide, phosphating, nitriding or hard chrome, as bare surfaces rust quickly.
T10A 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 | 0.95 – 1.04 | 1 |
| Si | ≤ 0.35 | 0.25 |
| Mn | ≤ 0.4 | 0.3 |
| Phigh-grade 'A' limit per GB/T 1298 | ≤ 0.03 | — |
| Shigh-grade 'A' limit per GB/T 1298 | ≤ 0.02 | — |
| Crresidual | ≤ 0.25 | — |
| Niresidual | ≤ 0.2 | — |
| Curesidual | ≤ 0.25 | — |
| Fe | balance | — |
T10A QT 45-50 HRC — frequently asked
What is T10A QT 45-50 HRC used for?
T10A QT 45-50 HRC is typically used for hand chisels, punches, woodworking tools and simple cold forming dies. In short: lowest-cost hardenable tool steel; water-hardening, shallow case; tougher than T12A.
What is the yield strength of T10A QT 45-50 HRC?
T10A QT 45-50 HRC has a typical yield strength of 1,400 MPa (203 ksi) and a tensile strength of 1,600 MPa (232 ksi) — stronger than 96% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is T10A QT 45-50 HRC easy to machine?
Not especially — machinability is rated poor (15/100, worse than 98% of steel grades). Machine only in the spheroidize-annealed state (~187 HB, ~65 % of AISI 1212); after hardening only grinding or EDM is practical.
Can T10A QT 45-50 HRC be welded?
Not readily — weldability is rated poor (15/100). Essentially unweldable for tool duty — high carbon causes hard, cracking-prone HAZ; if unavoidable preheat 250–300 °C and post-weld anneal immediately.
What surface finishes work on T10A QT 45-50 HRC?
Takes a fine polish when hardened; protect with oil, black oxide, phosphating, nitriding or hard chrome, as bare surfaces rust quickly.
Can T10A QT 45-50 HRC be formed, bent or molded?
Annealed strip bends and blanks acceptably with generous radii; hot forge 1050–850 °C then slow cool/anneal, never forge below 800 °C.
What is the maximum service temperature of T10A QT 45-50 HRC?
T10A QT 45-50 HRC is rated for continuous use to about 350°C (662 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between T10A Annealed and T10A-CD?
Annealed is the default condition — standard stocked condition for bar, plate and strip: soft, machinable and ready for the user's own hardening. CD: precision bar, drill rod and strip with tight size and good surface; slightly work-hardened, still hardenable. Yield strength is 400 MPa in Annealed versus 620 MPa in CD.
Sources
- GB/T 1298 Carbon Tool Steels — Technical Requirements — SAC (China) (2008)
- JIS G 4401 Carbon Tool Steels (SK105/SK3) — JISC (2009)
- ASTM A686 / AISI W1 Water-Hardening Tool Steel — ASTM (2016)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- Tool Steels, 5th ed. — ASM International (1998)
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.