Steel T1
AISI/SAE T1 · UNS T12001 · EN 1.3355 · JIS SKH2 · GB W18Cr4V
T1 (W18Cr4V, 1.3355) is the classic 18-4-1 tungsten high-speed steel, strengthened by tungsten, chromium and vanadium carbides for red hardness and wear resistance.
Values for the Annealed condition
T1 tempers and conditions
T1 is supplied in 2 conditions, soft to hard. Annealed is the default FabDigit quotes; the values on this page are for it.
Compare all 2 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AnnealedDefault spheroidize annealed bar/plate for machining | The as-supplied stock condition: soft enough (≤255 HB) to machine tool blanks before hardening. | 560 | 860 | 20 | 235 HB | — |
1260–1300 °C austenitize, oil/salt quench, 3× temper at 550–560 °C, 63–65 HRC | Full working condition for cutting tools — maximum hot hardness and wear resistance at the cost of toughness. | 2,200 | 0.5 | 64 HRC | — |
What is T1?
T1 (W18Cr4V, 1.3355) is the classic 18-4-1 tungsten high-speed steel, strengthened by tungsten, chromium and vanadium carbides for red hardness and wear resistance. It is bought as annealed bar and flats for cutting tools that must hold an edge at high cutting temperatures, then hardened and tempered to working hardness. Machinability is low (score 35) and any work after hardening means grinding or EDM; the high tungsten content makes it costlier than molybdenum grades, so M2 is the usual substitute. T1 has a density of 8.7 g/cm³ (0.314 lb/in³), heavier than 99% of steel grades. It melts at 1,340°C (2,444 °F). T1 has a yield strength of 560 MPa (81.2 ksi) and a tensile strength of 860 MPa (125 ksi) — stronger than 73% of steel grades. Elongation at break is 20% and the elastic modulus is 220 GPa (31.9 Msi).
What is T1 used for?
- Twist drills
- Milling cutters
- Reamers
Advantages
- Good corrosion resistance — 22/100, better than 90% of steel grades
Limitations
- Poor heat conductor — 21 W/m·K (12.1 BTU/hr·ft·°F), worse than 95% of steel grades
- High embodied carbon — 3.6 kg CO₂/kg, worse than 94% of steel grades
- Difficult to weld — 15/100, worse than 91% of steel grades
- Low electrical conductivity — 3.1 % IACS, worse than 89% of steel grades
- Limited formability — 15/100, worse than 87% of steel grades
T1 properties
Typical room-temperature values for T1-Annealed; bars are the position among steel grades.
Physical3
T1 has a density of 8.7 g/cm³ (0.314 lb/in³), heavier than 99% of steel grades. It melts at 1,340°C (2,444 °F).
Mechanical14
T1 has a yield strength of 560 MPa (81.2 ksi) and a tensile strength of 860 MPa (125 ksi) — stronger than 73% of steel grades. Elongation at break is 20% and the elastic modulus is 220 GPa (31.9 Msi).
Thermal6
T1 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 µm/m·K (6.11 µin/in·°F).
Electrical3
T1 conducts electricity at 3.1 % IACS, worse than 89% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (22/100), better than 90% of steel grades.
Sustainability4
Producing a kilogram of T1 takes about 52 MJ of energy and emits 3.6 kg of CO₂ — more than 94% of steel grades. Typical recycled content is 45%.
Manufacturability7
T1's machinability is fair (35/100, worse than 84% of steel grades); weldability poor (15/100); formability poor (15/100).
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. T1 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with T1
Is T1 easy to machine?
Machine only in the annealed condition with rigid setups, sharp cobalt-HSS or coated-carbide tooling and low speeds; after hardening only grinding (CBN/SiC wheels) or EDM is practical.
Can T1 be welded?
Not a structural weld metal — repair weld with matching HSS electrodes at 500–550 °C preheat, then immediately re-temper; risk of quench cracking is high.
Can T1 be formed, bent or molded?
Hot forge 1100–1150 °C (never below ~900 °C), cool slowly and full-anneal at 850–900 °C; cold forming is impractical.
Manufacturability
The process limits FabDigit applies to T1. Every T1 part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
CNC machining
| Machinability | Poor35 / 100 |
|---|---|
| ISO material group | P.2 |
| Cutting speed (rough / finish) | 180 / 210 m/min |
| Minimum wall | 0.8 mm |
| Minimum internal radius | 1 mm |
| Drill depth limit | 5× diameter |
| Best surface (machined / polished) | Ra 1.6 / — |
| Hardenable after machining | No |
T1 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 standards allow up to 0.80 C for higher wear resistance | 0.65 – 0.8 | 0.73 |
| Wprimary hot-hardness carbide former | 17.25 – 18.75 | 18 |
| Cr | 3.75 – 4.5 | 4.1 |
| V | 0.9 – 1.3 | 1.1 |
| Mn | 0.1 – 0.4 | 0.25 |
| Si | 0.2 – 0.4 | 0.3 |
| Mooptional/residual in some specifications | ≤ 1 | 0.3 |
| P | ≤ 0.03 | |
| S | ≤ 0.03 | |
| Fe | balance |
What surface finishes work on T1?
Black-oxide, steam-blue, nitride or PVD TiN/TiAlN coatings are standard for cutting tools; unprotected surfaces must be oiled since the 4 % Cr gives no stainless behaviour.
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).
Plating
CVD Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel T1 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
How much does T1 cost?
T1 is a premium-cost steel ($$$), pricier than about 57% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
T1 — frequently asked
What is T1 used for?
T1 is typically used for twist drills, milling cutters and reamers. In short: workhorse high-speed tool.
What is the yield strength of T1?
T1 has a typical yield strength of 560 MPa (81.2 ksi) and a tensile strength of 860 MPa (125 ksi) — stronger than 73% of steel grades. Strength varies by condition: see the 2 listed tempers.
Is T1 easy to machine?
Not especially — machinability is rated fair (35/100, worse than 84% of steel grades). Machine only in the annealed condition with rigid setups, sharp cobalt-HSS or coated-carbide tooling and low speeds; after hardening only grinding (CBN/SiC wheels) or EDM is practical.
Can T1 be welded?
Not readily — weldability is rated poor (15/100). Not a structural weld metal — repair weld with matching HSS electrodes at 500–550 °C preheat, then immediately re-temper; risk of quench cracking is high.
What surface finishes work on T1?
Black-oxide, steam-blue, nitride or PVD TiN/TiAlN coatings are standard for cutting tools; unprotected surfaces must be oiled since the 4 % Cr gives no stainless behaviour.
Can T1 be formed, bent or molded?
Hot forge 1100–1150 °C (never below ~900 °C), cool slowly and full-anneal at 850–900 °C; cold forming is impractical.
What is the maximum service temperature of T1?
T1 is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does T1 cost?
T1 is a premium-cost steel ($$$), pricier than about 57% 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.
Can FabDigit make parts in T1?
Yes — T1 is available for CNC machining; every part is priced by an engineer rather than instantly. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM A600 — Standard Specification for Tool Steel High Speed — ASTM International (2016)
- GB/T 9943 (W18Cr4V) (2008)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys (Tool Steels) — ASM International (1990)
- ASM Handbook Vol.4 — Heat Treating (High-Speed Tool Steels) — ASM International (1991)
- Machinery's Handbook — Tool Steels and Machinability Ratings — Industrial Press (2020)
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.