Steel T15-ANN (Annealed)
Heat-treated state · default condition
AISI/SAE T15 · UNS T12015 · EN 1.3202 · JIS SKH10 · GB W12Cr4V5Co5
Standard as-supplied stock condition for machining tool blanks before hardening.
Values for the ANN condition
Other T15 tempers and conditions
T15 is listed in 5 conditions; see the grade overview at T15.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ANNDefaultThis page Annealed | Standard as-supplied stock condition for machining tool blanks before hardening. | 500 | 830 | 12 | 24 HRC | 21 W/m·K |
Hardened & triple tempered to 60–62 HRC | Lower austenitizing / higher temper for interrupted cuts, punches and cold-work tooling where chipping is the risk. | — | 2,100 | 1 | 61 HRC | 23 W/m·K |
Hardened & triple tempered to 65–67 HRC | High austenitizing temperature for peak hardness and red hardness in abrasive, continuous cuts; lowest toughness. | — | 2,200 | 0.3 | 66 HRC | — |
Hardened & triple tempered to 63–65 HRC | Austenitize ~1210–1230 °C, quench, triple temper 540–560 °C — the usual working hardness for cutting tools. | — | 2,300 | 0.5 | 64 HRC | 24 W/m·K |
Powder-metallurgy T15 (CPM T15 type), hardened 65–67 HRC | Choose PM route for fine, uniform vanadium carbides — much better toughness, grindability and dimensional stability at equal hardness. | — | 2,500 | — | 66 HRC | — |
What is T15-ANN?
T15-ANN is T15 heat treated to ANN — standard as-supplied stock condition for machining tool blanks before hardening. T15-ANN has a yield strength of 500 MPa (72.5 ksi) and a tensile strength of 830 MPa (120 ksi) — stronger than 63% of steel grades. Elongation at break is 12% and the elastic modulus is 216 GPa (31.3 Msi). T15-ANN has a density of 8.19 g/cm³ (0.296 lb/in³), heavier than 98% of steel grades. It melts at 1,230°C (2,246 °F).
Advantages
- Polishes to a fine finish — 70/100, better than 87% of steel grades
Limitations
- Low electrical conductivity — 2.7 % IACS, worse than 96% of steel grades
- Poor heat conductor — 21 W/m·K (12.1 BTU/hr·ft·°F), worse than 95% of steel grades
- Difficult to machine — 22/100, worse than 95% of steel grades
- High embodied carbon — 3.8 kg CO₂/kg, worse than 94% of steel grades
- Limited formability — 12/100, worse than 92% of steel grades
T15-ANN properties
Typical room-temperature values for T15-ANN; 18 are specific to this condition. Other listed values are T15 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
T15-ANN has a density of 8.19 g/cm³ (0.296 lb/in³), heavier than 98% of steel grades. It melts at 1,230°C (2,246 °F).
Mechanical13
T15-ANN has a yield strength of 500 MPa (72.5 ksi) and a tensile strength of 830 MPa (120 ksi) — stronger than 63% of steel grades. Elongation at break is 12% and the elastic modulus is 216 GPa (31.3 Msi).
Thermal6
T15-ANN is rated for continuous service to 400°C (752 °F). It conducts heat at 21 W/m·K (12.1 BTU/hr·ft·°F), worse than 95% of steel grades. Thermal expansion is 11.2 µm/m·K (6.22 µin/in·°F).
Electrical3
T15-ANN conducts electricity at 2.7 % IACS, worse than 96% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (15/100), better than 75% of steel grades.
Sustainability4
Producing a kilogram of T15-ANN takes about 52 MJ of energy and emits 3.8 kg of CO₂ — more than 94% of steel grades. Typical recycled content is 30%.
Manufacturability7
T15-ANN's machinability is poor (22/100, worse than 95% of steel grades); weldability poor (20/100); formability not recommended (12/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with T15-ANN
Is T15 easy to machine?
Machine only in the annealed condition with rigid setups, low speeds and cobalt-HSS or coated-carbide tooling; the 5% V carbides also make grinding slow — use CBN or friable SG alumina wheels.
Can T15 be welded?
Not a structural weld metal; repair-weld only with matching HSS filler, 500–550 °C preheat/interpass and immediate re-temper.
Can T15 be formed, bent or molded?
Hot-work only (forge 1100–1150 °C, stop above 950 °C, slow cool then anneal 870–900 °C); no cold forming.
What surface finishes work on T15?
Salt-bath nitride, steam oxide, black oxide or PVD TiN/TiAlN after final grinding; oil or VCI protect since the 4% Cr gives no stainless behaviour.
T15 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 |
|---|---|---|
| Csome producers supply 1.45–1.60 | 1.5 – 1.6 | 1.55 |
| W | 11.75 – 13 | 12.25 |
| Cr | 3.75 – 5 | 4.25 |
| Vprimary MC carbide former | 4.5 – 5.25 | 5 |
| Cored-hardness booster | 4.75 – 5.25 | 5 |
| Mooptional/residual | ≤ 1 | 0.5 |
| Mn | 0.15 – 0.4 | 0.28 |
| Si | 0.15 – 0.4 | 0.28 |
| P | ≤ 0.03 | — |
| S | ≤ 0.03 | — |
| Fe | balance | — |
T15-ANN — frequently asked
What is T15-ANN used for?
T15-ANN is typically used for high-production cutting tools, form tools, punches for abrasive materials and heavy-duty lathe tools. In short: highest wear resistance HSS; cobalt red-hardness grade; hardest to grind.
What is the yield strength of T15-ANN?
T15-ANN has a typical yield strength of 500 MPa (72.5 ksi) and a tensile strength of 830 MPa (120 ksi) — stronger than 63% of steel grades. Strength varies by condition: see the 5 listed tempers.
Is T15-ANN easy to machine?
Not especially — machinability is rated poor (22/100, worse than 95% of steel grades). Machine only in the annealed condition with rigid setups, low speeds and cobalt-HSS or coated-carbide tooling; the 5% V carbides also make grinding slow — use CBN or friable SG alumina wheels.
Can T15-ANN be welded?
Not readily — weldability is rated poor (20/100). Not a structural weld metal; repair-weld only with matching HSS filler, 500–550 °C preheat/interpass and immediate re-temper.
What surface finishes work on T15-ANN?
Salt-bath nitride, steam oxide, black oxide or PVD TiN/TiAlN after final grinding; oil or VCI protect since the 4% Cr gives no stainless behaviour.
Can T15-ANN be formed, bent or molded?
Hot-work only (forge 1100–1150 °C, stop above 950 °C, slow cool then anneal 870–900 °C); no cold forming.
What is the maximum service temperature of T15-ANN?
T15-ANN 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.
Sources
- ASTM A600 — Standard Specification for Tool Steel High Speed — ASTM International (2016)
- GB/T 9943 (W12Cr4V5Co5) (2008)
- ASM Handbook Vol.1: Properties and Selection — Irons, Steels, and High-Performance Alloys (Tool Steels) — ASM International (1990)
- Tool Steels, 5th ed. — ASM International (1998)
- CPM T15 / T15 high speed steel data sheets — Crucible Industries / Böhler-Uddeholm (2020)
- JIS G4403 SKH10 / EN ISO 4957 HS12-1-5-5 (1.3202) — JISC / ISO (2018)
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.