Steel T9A
GB T9A
T9A is a ~0.9 %C plain carbon tool steel from the T7–T13 (SK) family, hardened by quenching and low tempering rather than by alloy carbides, and stocked hot rolled, annealed, cold drawn, normalized or quenched and tempered to 54–62 HRC.
Reference datasheet — T9A is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the A condition
T9A tempers and conditions
T9A is supplied in 9 conditions, soft to hard. A is the default FabDigit quotes; the values on this page are for it.
Compare all 9 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ADefault Solution annealed | Choose as the standard stock condition at 190 HB (=207 HB max): spheroidized pearlite turns, mills, drills and cold-blanks well before quench hardening. | 410 | 700 | 22 | 190 HB | — |
Stress relieved | Apply after rough machining to remove residual stress at 600-650 °C and limit quench distortion in long thin sections and precision punches. | 420 | 710 | 20 | 195 HB | 9.8 % IACS |
Hot rolled | Pick as the lowest-cost as-rolled blank; hardness around 240 HB and uneven structure normally require spheroidize annealing before machining. | 470 | 830 | 12 | 22 HRC | 9.6 % IACS |
Normalized | Apply after forging to break up coarse structure and carbide networks by air cooling from 800-830 °C, preparing the microstructure for spheroidize annealing or hardening. | 500 | 880 | 12 | 25 HRC | 9.5 % IACS |
Cold drawn | Use for small-section bar and strip needing tight tolerances and good surface; cold drawing lifts yield to 620 MPa but leaves residual stress, so stress relieve before finishing. | 620 | 800 | 10 | 21 HRC | 9.6 % IACS |
Q&T 54–56 HRC | Choose for punches, rivet sets and air chisels under heavy impact; the ~250 °C temper after water quenching gives the toughest working hardness at some loss of wear resistance. | 1,600 | 1,900 | 2 | 55 HRC | — |
Q&T 56–58 HRC | Pick as the general-purpose working hardness for small cold-blanking dies, shear blades and woodworking tools, where the ~220 °C temper balances hardness and toughness. | 1,750 | 2,050 | 1.5 | 57 HRC | — |
Q&T 58–60 HRC | Use for wear-dominated punches, center punches and small blades; the ~180 °C temper leaves only 1% elongation, so avoid sharp corners and stress concentrations. | 1,900 | 2,200 | 1 | 59 HRC | — |
Q&T 60–62 HRC | Specify only for thin, small cutting edges and gauges with almost no impact; the 150-170 °C stress-relief temper retains maximum wear hardness (GB quenched hardness =62 HRC). | 2,350 | 0.5 | 61 HRC | — |
What is T9A?
T9A is a ~0.9 %C plain carbon tool steel from the T7–T13 (SK) family, hardened by quenching and low tempering rather than by alloy carbides, and stocked hot rolled, annealed, cold drawn, normalized or quenched and tempered to 54–62 HRC. Engineers use it for punches and small forming dies where toughness matters as much as hardness, usually in bar, flat and strip form. Hardenability is shallow, there is no corrosion resistance, and the service limit is about 300 °C. T13A gives more wear resistance at lower toughness; A5 is the nearest air-hardening alternative. T9A 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). T9A has a yield strength of 410 MPa (59.5 ksi) and a tensile strength of 700 MPa (102 ksi) — weaker than 57% of steel grades. Elongation at break is 22% and the elastic modulus is 210 GPa (30.5 Msi).
What is T9A used for?
- punches
- scribers
- stamping dies
Advantages
- Polishes to a fine finish — 70/100, better than 87% 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 — 15/100, worse than 91% of steel grades
- Limited service temperature — 300°C (572 °F), worse than 78% of steel grades
T9A properties
Typical room-temperature values for T9A-A; bars are the position among steel grades.
Physical3
T9A 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).
Mechanical15
T9A has a yield strength of 410 MPa (59.5 ksi) and a tensile strength of 700 MPa (102 ksi) — weaker than 57% of steel grades. Elongation at break is 22% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
T9A 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
T9A conducts electricity at 9.6 % IACS, better than 78% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 86% of steel grades.
Sustainability4
Producing a kilogram of T9A takes about 26 MJ of energy and emits 2 kg of CO₂ — less than 64% of steel grades. Typical recycled content is 25%.
Manufacturability8
T9A's machinability is good (55/100, better than 62% of steel grades); weldability poor (15/100); formability fair (40/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the steel family
Yield strength against density for every steel grade FabDigit runs. T9A is highlighted; hover a dot for its name, or open the interactive family chart.
Working with T9A
Is T9A easy to machine?
In the spheroidize-annealed condition (≤207 HB) machinability is good with either HSS or coated carbide tooling. Once hardened, only grinding or EDM is practical.
Can T9A be welded?
At about 0.9 %C weldability is poor and hardening cracks form readily. If repair welding is unavoidable, preheat to 250–350 °C, use a matching high-carbon filler and temper immediately.
Can T9A be formed, bent or molded?
Annealed material can be cold blanked, bent and lightly cold headed. Hot work at approximately 1050–850 °C, cool slowly after forging and spheroidize anneal promptly to break up network carbides.
T9A 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 | 0.85 – 0.94 | 0.9 |
| Si | ≤ 0.35 | 0.25 |
| Mn | ≤ 0.4 | 0.3 |
| Phigh-quality (A) grade limit | ≤ 0.03 | |
| Shigh-quality (A) grade limit | ≤ 0.02 | |
| Crresidual element | ≤ 0.1 | |
| Niresidual element | ≤ 0.12 | |
| Curesidual element | ≤ 0.2 | |
| Fe | balance |
What surface finishes work on T9A?
After hardening it can be finish ground and polished to a mirror surface. Corrosion protection relies on black oxide, phosphating, chrome plating or oiling; it cannot be anodized, and plated parts should be baked at 190 °C for hydrogen relief.
Surface treatments FabDigit runs on steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Organic Coating
Black / Phosphate
Thermal Spray
How much does T9A cost?
T9A is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
T9A — frequently asked
What is T9A used for?
T9A is typically used for punches, scribers and stamping dies. In short: balanced hardness and toughness; low-cost punch steel; shallow-hardening carbon grade.
What is the yield strength of T9A?
T9A has a typical yield strength of 410 MPa (59.5 ksi) and a tensile strength of 700 MPa (102 ksi) — weaker than 57% of steel grades. Strength varies by condition: see the 9 listed tempers.
Is T9A easy to machine?
Reasonably — machinability is rated good (55/100, better than 62% of steel grades). In the spheroidize-annealed condition (≤207 HB) machinability is good with either HSS or coated carbide tooling. Once hardened, only grinding or EDM is practical.
Can T9A be welded?
Not readily — weldability is rated poor (15/100). At about 0.9 %C weldability is poor and hardening cracks form readily. If repair welding is unavoidable, preheat to 250–350 °C, use a matching high-carbon filler and temper immediately.
What surface finishes work on T9A?
After hardening it can be finish ground and polished to a mirror surface. Corrosion protection relies on black oxide, phosphating, chrome plating or oiling; it cannot be anodized, and plated parts should be baked at 190 °C for hydrogen relief.
Can T9A be formed, bent or molded?
Annealed material can be cold blanked, bent and lightly cold headed. Hot work at approximately 1050–850 °C, cool slowly after forging and spheroidize anneal promptly to break up network carbides.
What is the maximum service temperature of T9A?
T9A 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 T9A-A and T9A-CD?
A is the default condition — choose as the standard stock condition at 190 HB (=207 HB max): spheroidized pearlite turns, mills, drills and cold-blanks well before quench hardening. CD: use for small-section bar and strip needing tight tolerances and good surface; cold drawing lifts yield to 620 MPa but leaves residual stress, so stress relieve before finishing. Yield strength is 410 MPa in A versus 620 MPa in CD.
How much does T9A cost?
T9A is a budget-cost steel ($), cheaper than about 90% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- ASTM A686 Standard Specification for Tool Steel, Carbon (W1 ) — ASTM International (2020)
- JIS G 4401 (SK95/SK4 ) — JISC (2009)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels — ASM International (1990)
- ASM Handbook Vol.4 — Heat Treating (Water-hardening tool steels) — ASM International (1991)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.