Steel T9-A (Solution annealed)
Temper · default condition
AISI/SAE T9
Choose the spheroidize annealed as-supplied bar or plate for the lowest hardness (180 HB) and easiest turning, milling, drilling and cold working before final quench hardening.
Values for the A condition
Other T9 tempers and conditions
T9 is listed in 8 conditions; see the grade overview at T9.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
High-grade quality | Specify the high-grade quality variant with lower phosphorus and sulphur and tighter control of inclusions and carbide non-uniformity for precision dies and cutting tools. | 395 | 650 | 22 | 62 HRC | 9.8 % IACS |
ADefaultThis page Solution annealed | Choose the spheroidize annealed as-supplied bar or plate for the lowest hardness (180 HB) and easiest turning, milling, drilling and cold working before final quench hardening. | 400 | 660 | 20 | 180 HB | — |
Hot rolled | Take hot rolled or hot forged untreated stock only as a blank; its network carbides require spheroidize annealing before machining or hardening. | 450 | 790 | 12 | 21 HRC | 9.4 % IACS |
Normalized | Normalize at 800–840 °C with air cooling to break up forging carbide networks and refine the structure in preparation for spheroidize annealing or quenching, not as a final state. | 470 | 830 | 10 | 25 HRC | 9.3 % IACS |
Cold drawn | Pick annealed-then-cold-drawn bar or cold rolled strip for tight size tolerance and smooth surface in small sections; hardness rises to 230 HB while elongation drops to 8%. | 620 | 800 | 8 | 20 HRC | 9.5 % IACS |
Q&T 45–52 HRC | Temper at 300–400 °C to 45–52 HRC when chisels, punches and spring parts see heavy impact; wear resistance is sacrificed for 1400 MPa yield and 4% elongation. | 1,400 | 1,650 | 4 | 49 HRC | — |
Q&T 56–60 HRC | Choose tempering at 200–250 °C to 56–60 HRC when blanking dies, shear blades and hand tools must absorb some impact, trading peak wear resistance for toughness. | 1,750 | 1,950 | 1 | 58 HRC | 8.6 % IACS |
Q&T 60–63 HRC | Use water quenching from 760–780 °C with 150–180 °C tempering for maximum hardness (60–63 HRC) and wear resistance in punches, chisels and woodworking blades; toughness is minimal. | — | 2,100 | 1 | 62 HRC | — |
What is T9-A?
T9-A is T9 in the A temper — choose the spheroidize annealed as-supplied bar or plate for the lowest hardness (180 HB) and easiest turning, milling, drilling and cold working before final quench hardening. T9-A has a yield strength of 400 MPa (58 ksi) and a tensile strength of 660 MPa (95.7 ksi) — weaker than 60% of steel grades. Elongation at break is 20% and the elastic modulus is 207 GPa (30 Msi). T9-A 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).
Advantages
- Polishes to a fine finish — 72/100, better than 92% of steel grades
- 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
- High electrical conductivity — 9.6 % IACS, better than 78% of steel grades
Limitations
- Difficult to weld — 12/100, worse than 96% of steel grades
- Limited service temperature — 300°C (572 °F), worse than 78% of steel grades
T9-A properties
Typical room-temperature values for T9-A; 13 are specific to this condition. Other listed values are T9 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
T9-A 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
T9-A has a yield strength of 400 MPa (58 ksi) and a tensile strength of 660 MPa (95.7 ksi) — weaker than 60% of steel grades. Elongation at break is 20% and the elastic modulus is 207 GPa (30 Msi).
Thermal6
T9-A is rated for continuous service to 300°C (572 °F). It conducts heat at 48 W/m·K (27.7 BTU/hr·ft·°F), better than 79% of steel grades. Thermal expansion is 11.5 µm/m·K (6.39 µin/in·°F).
Electrical3
T9-A conducts electricity at 9.6 % IACS, better than 78% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (8/100), worse than 99% of steel grades.
Sustainability4
Producing a kilogram of T9-A takes about 25 MJ of energy and emits 1.9 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 25%.
Manufacturability7
T9-A's machinability is fair (45/100, worse than 65% of steel grades); weldability not recommended (12/100); formability fair (35/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with T9-A
Is T9 easy to machine?
Turning, milling, drilling and tapping are all practical in the spheroidize-annealed condition (≤192 HB) using HSS or coated carbide with ample coolant; after hardening only grinding or EDM is possible.
Can T9 be welded?
Poor weldability — at about 0.9 % C martensite and cracking are almost unavoidable, so T9 is normally not welded. If repair is unavoidable, preheat 250–350 °C, use low-hydrogen consumables and temper immediately.
Can T9 be formed, bent or molded?
The annealed condition allows light cold bending and blanking, but formability is limited. Forge from 1050–1100 °C with a finishing temperature no lower than 800 °C, then slow-cool and spheroidize-anneal; harden from 760–780 °C in water or brine, noting the shallow hardening depth and high distortion and cracking risk.
What surface finishes work on T9?
No corrosion resistance: specify black oxide (alkaline blackening), phosphating, chrome plating or rust-preventive oil. Hardened parts can be ground and polished to a mirror finish, but watch for grinding burn and temper softening.
T9 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 |
|---|---|---|
| CGB/T 1298 | 0.85 – 0.94 | 0.9 |
| Si | ≤ 0.35 | 0.22 |
| Mn | ≤ 0.4 | 0.25 |
| PT9A ≤0.030 | ≤ 0.04 | — |
| ST9A ≤0.020 | ≤ 0.03 | — |
| Crresidual element | ≤ 0.25 | — |
| Niresidual element | ≤ 0.2 | — |
| Curesidual element | ≤ 0.3 | — |
| Fe | balance | — |
T9-A — frequently asked
What is T9-A used for?
T9-A is typically used for punches, dies, cutting tools and woodworking tools. In short: mid-carbon T-series tool steel; balanced wear and toughness; water-hardening, shallow case.
What is the yield strength of T9-A?
T9-A has a typical yield strength of 400 MPa (58 ksi) and a tensile strength of 660 MPa (95.7 ksi) — weaker than 60% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is T9-A easy to machine?
Reasonably — machinability is rated fair (45/100, worse than 65% of steel grades). Turning, milling, drilling and tapping are all practical in the spheroidize-annealed condition (≤192 HB) using HSS or coated carbide with ample coolant; after hardening only grinding or EDM is possible.
Can T9-A be welded?
Not readily — weldability is rated not recommended (12/100). Poor weldability — at about 0.9 % C martensite and cracking are almost unavoidable, so T9 is normally not welded. If repair is unavoidable, preheat 250–350 °C, use low-hydrogen consumables and temper immediately.
What surface finishes work on T9-A?
No corrosion resistance: specify black oxide (alkaline blackening), phosphating, chrome plating or rust-preventive oil. Hardened parts can be ground and polished to a mirror finish, but watch for grinding burn and temper softening.
Can T9-A be formed, bent or molded?
The annealed condition allows light cold bending and blanking, but formability is limited. Forge from 1050–1100 °C with a finishing temperature no lower than 800 °C, then slow-cool and spheroidize-anneal; harden from 760–780 °C in water or brine, noting the shallow hardening depth and high distortion and cracking risk.
What is the maximum service temperature of T9-A?
T9-A is rated for continuous use to about 300°C (572 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between T9-A and T9 QT-58?
A is the default condition — choose the spheroidize annealed as-supplied bar or plate for the lowest hardness (180 HB) and easiest turning, milling, drilling and cold working before final quench hardening. QT-58: choose tempering at 200–250 °C to 56–60 HRC when blanking dies, shear blades and hand tools must absorb some impact, trading peak wear resistance for toughness. Yield strength is 400 MPa in A versus 1,750 MPa in QT-58.
Sources
- ASM Handbook Vol.1: Properties and Selection — Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.4: Heat Treating (water-hardening tool steels, W1) — ASM International (1991)
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.