Steel W1
AISI/SAE W1 · UNS T72301
W1 (T72301 / T8 / SK3) is the basic water-hardening plain-carbon tool steel: 0.7–1.5 % carbon gives up to 64–65 HRC surface hardness after a water or brine quench, with excellent edge retention at low cost.
Values for the Annealed condition
W1 tempers and conditions
W1 is supplied in 5 conditions, soft to hard. Annealed is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Stress Relieved (annealed + 600–650 °C relief after rough machining) | Intermediate step for thin or asymmetric parts to cut distortion during the subsequent water quench. | 440 | 740 | 23 | 195 HB | 9.5 % IACS |
AnnealedDefault soft, spheroidized-carbide supply condition | Default stock condition for bar, flat and drill rod — machine, form and file it, then harden. | 460 | 760 | 22 | 200 HB | — |
Hot Rolled (as-rolled / mill scale, unannealed) | Cheapest large-section supply form; expect a hard pearlitic skin and decarburized layer — anneal before machining. | 520 | 900 | 12 | 21 HRC | 9.5 % IACS |
Cold Drawn / precision ground annealed (drill rod, flat ground stock) | Choose when you want close diameter tolerance and a bright surface straight from stock (classic W1 drill rod). | 620 | 830 | 14 | 16 HRC | 9.5 % IACS |
brine quench + 150–200 °C stress-relief temper, 62–65 HRC | Maximum hardness and wear/edge retention for files, razors, scrapers and engraving tools; accept brittleness and shallow case. | 2,000 | 2,300 | 1 | 64 HRC | — |
What is W1?
W1 (T72301 / T8 / SK3) is the basic water-hardening plain-carbon tool steel: 0.7–1.5 % carbon gives up to 64–65 HRC surface hardness after a water or brine quench, with excellent edge retention at low cost. It machines easily in the annealed state and is the traditional choice for hand chisels, files, punches, gravers, woodworking blades and low-cost dies, stocked as annealed, hot-rolled and cold-drawn bar and flat. Hardening is shallow (roughly 3–6 mm effective case), water quenching brings distortion and cracking risk, tempering resistance is poor above about 200 °C, and there is no corrosion resistance. Choose O1, A2 or D2 when dimensional stability or deep hardening is required. W1 has a density of 7.83 g/cm³ (0.283 lb/in³), lighter than 80% of steel grades. It melts at 1,425°C (2,597 °F). W1 has a yield strength of 460 MPa (66.7 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 55% of steel grades. Elongation at break is 22% and the elastic modulus is 205 GPa (29.7 Msi).
What is W1 used for?
- Hand chisels
- Woodworking tools
- Scissors
Advantages
- Polishes to a fine finish — 75/100, better than 94% 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 — 9.5 % IACS, better than 75% 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
W1 properties
Typical room-temperature values for W1-Annealed; bars are the position among steel grades.
Physical3
W1 has a density of 7.83 g/cm³ (0.283 lb/in³), lighter than 80% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical15
W1 has a yield strength of 460 MPa (66.7 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 55% of steel grades. Elongation at break is 22% and the elastic modulus is 205 GPa (29.7 Msi).
Thermal6
W1 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 12.4 µm/m·K (6.89 µin/in·°F).
Electrical3
W1 conducts electricity at 9.5 % IACS, better than 75% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (8/100), worse than 99% of steel grades.
Sustainability4
Producing a kilogram of W1 takes about 32 MJ of energy and emits 2.2 kg of CO₂ — more than 70% of steel grades. Typical recycled content is 30%.
Manufacturability7
W1's machinability is fair (45/100, worse than 65% of steel grades); weldability poor (15/100); formability fair (35/100).
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. W1 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with W1
Is W1 easy to machine?
Machines readily in the spheroidize-annealed state (~30 % of AISI 1212) with sharp HSS or coated carbide; above ~55 HRC only grinding, EDM or CBN turning is practical.
Can W1 be welded?
Poor weldability — high carbon promotes quench cracking; if unavoidable preheat 250–350 °C, use matching or low-hydrogen filler and temper immediately after.
Can W1 be formed, bent or molded?
Hot forge 900–1050 °C (never below ~850 °C) then slow-cool and spheroidize anneal 740–760 °C; cold bending is limited and should be done annealed with generous radii.
Manufacturability
The process limits FabDigit applies to W1. Every W1 part is priced by an engineer; design inside these and the quote comes back without a redesign loop.
CNC machining
| Machinability | Fair45 / 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 |
W1 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 |
|---|---|---|
| Csupplied in graded carbon levels (e.g. W1-8 ≈ 0.80 %C, W1-10 ≈ 1.00 %C, W1-13 ≈ 1.30 %C) per ASTM A686 | 0.7 – 1.5 | 1 |
| Mn | 0.1 – 0.4 | 0.25 |
| Si | 0.1 – 0.4 | 0.25 |
| P | ≤ 0.03 | |
| S | ≤ 0.03 | |
| Crresidual max | ≤ 0.15 | |
| Niresidual max | ≤ 0.2 | |
| Curesidual max | ≤ 0.2 | |
| Moresidual max | ≤ 0.1 | |
| Vresidual max; V-modified W1 variants up to 0.35 | ≤ 0.1 | |
| Wresidual max | ≤ 0.15 | |
| Fe | balance |
What surface finishes work on W1?
Takes a very fine ground and polished edge; no anodizing — protect with oil, black oxide, phosphate or thin chrome/nitride coatings since bare W1 rusts quickly.
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 W1 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
How much does W1 cost?
W1 is a premium-cost steel ($$$), cheaper than about 59% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
W1 — frequently asked
What is W1 used for?
W1 is typically used for hand chisels, woodworking tools and scissors. In short: sharpest cutting edge.
What is the yield strength of W1?
W1 has a typical yield strength of 460 MPa (66.7 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 55% of steel grades. Strength varies by condition: see the 5 listed tempers.
Is W1 easy to machine?
Reasonably — machinability is rated fair (45/100, worse than 65% of steel grades). Machines readily in the spheroidize-annealed state (~30 % of AISI 1212) with sharp HSS or coated carbide; above ~55 HRC only grinding, EDM or CBN turning is practical.
Can W1 be welded?
Not readily — weldability is rated poor (15/100). Poor weldability — high carbon promotes quench cracking; if unavoidable preheat 250–350 °C, use matching or low-hydrogen filler and temper immediately after.
What surface finishes work on W1?
Takes a very fine ground and polished edge; no anodizing — protect with oil, black oxide, phosphate or thin chrome/nitride coatings since bare W1 rusts quickly.
Can W1 be formed, bent or molded?
Hot forge 900–1050 °C (never below ~850 °C) then slow-cool and spheroidize anneal 740–760 °C; cold bending is limited and should be done annealed with generous radii.
What is the maximum service temperature of W1?
W1 is rated for continuous use to about 300°C (572 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does W1 cost?
W1 is a premium-cost steel ($$$), cheaper than about 59% 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 W1?
Yes — W1 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 A686 — Standard Specification for Tool Steel, Carbon — ASTM International (2020)
- ASM Handbook Vol. 1: Properties and Selection — Irons, Steels, and High-Performance Alloys (Tool Steels) — ASM International (1990)
- ASM Specialty Handbook: Tool Materials — ASM International (1995)
- ASM Handbook Vol. 16: Machining — ASM International (1989)
- GB/T 1298 T7A–T13A (2008)
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.