Steel D1
AISI/SAE D1 · UNS T30401
D1 is a high-carbon, high-chromium air-hardening cold-work tool steel (UNS T30401) closely related to D2, with about 12 % Cr forming the chromium carbides that carry its wear resistance.
Reference datasheet — D1 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
D1 tempers and conditions
D1 is supplied in 6 conditions, soft to hard. A is the default FabDigit quotes; the values on this page are for it.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ADefault Solution annealed | Standard mill-supplied condition for machining the die before hardening. | 420 | 760 | 16 | 235 HB | — |
Hardened & high-temperature tempered ~500–540 °C, 52–56 HRC | Choose when tools run warm or need extra toughness/dimensional stability, or before nitriding. | 1,500 | 1,750 | 3 | 54 HRC | — |
Hardened & tempered ~200–260 °C, 57–59 HRC | Best general-purpose balance of wear resistance and chipping resistance for cold-work dies. | 1,600 | 1,900 | 2 | 58 HRC | — |
Hardened & tempered ~150–200 °C, 60–62 HRC | Maximum wear resistance for blanking/trimming dies on thin, non-abusive work. | 1,700 | 2,000 | 1 | 61 HRC | — |
Hardened, tempered and gas/plasma nitrided surface | Adds a very hard, galling-resistant case for forming stainless or coated sheet; core stays at temper hardness. | 1,700 | 1,950 | 1 | 58 HRC | 2.6 % IACS |
Hardened + deep-freeze (cryogenic) + double temper, 61–63 HRC | Use where residual austenite must be eliminated for size stability (gauges, precision punches). | 1,850 | 2,100 | 0.5 | 62 HRC | 2.6 % IACS |
What is D1?
D1 is a high-carbon, high-chromium air-hardening cold-work tool steel (UNS T30401) closely related to D2, with about 12 % Cr forming the chromium carbides that carry its wear resistance. It is specified for blanking, forming and thread-rolling dies on long production runs and is supplied annealed, then hardened to roughly 54–62 HRC, optionally cryogenically treated or nitrided. Annealed machinability is low, the material is grind/EDM-only once hardened, service is limited to about 200 °C and the 12 % Cr is not enough to prevent rusting in storage. A5 machines more easily at lower wear resistance. D1 has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 95% of steel grades. It melts at 1,421°C (2,590 °F). D1 has a yield strength of 420 MPa (60.9 ksi) and a tensile strength of 760 MPa (110 ksi) — weaker than 53% of steel grades. Elongation at break is 16% and the elastic modulus is 207 GPa (30 Msi).
What is D1 used for?
- blanking dies
- forming dies
- thread rolling dies
Advantages
- Good corrosion resistance — 28/100, better than 94% of steel grades
- Polishes to a fine finish — 70/100, better than 87% of steel grades
Limitations
- Low fracture toughness — 30 MPa·√m (27.3 ksi·√in), worse than 96% of steel grades
- Poor heat conductor — 20 W/m·K (11.6 BTU/hr·ft·°F), worse than 96% of steel grades
- Low electrical conductivity — 2.7 % IACS, worse than 96% of steel grades
- Limited service temperature — 200°C (392 °F), worse than 93% of steel grades
- Difficult to weld — 15/100, worse than 91% of steel grades
D1 properties
Typical room-temperature values for D1-A; bars are the position among steel grades.
Physical3
D1 has a density of 7.7 g/cm³ (0.278 lb/in³), lighter than 95% of steel grades. It melts at 1,421°C (2,590 °F).
Mechanical16
D1 has a yield strength of 420 MPa (60.9 ksi) and a tensile strength of 760 MPa (110 ksi) — weaker than 53% of steel grades. Elongation at break is 16% and the elastic modulus is 207 GPa (30 Msi).
Thermal6
D1 is rated for continuous service to 200°C (392 °F). It conducts heat at 20 W/m·K (11.6 BTU/hr·ft·°F), worse than 96% of steel grades. Thermal expansion is 10.4 µm/m·K (5.78 µin/in·°F).
Electrical3
D1 conducts electricity at 2.7 % IACS, worse than 96% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (28/100), better than 94% of steel grades.
Sustainability4
Producing a kilogram of D1 takes about 35 MJ of energy and emits 2.6 kg of CO₂ — more than 87% of steel grades. Typical recycled content is 35%.
Manufacturability7
D1's machinability is fair (35/100, worse than 84% of steel grades); weldability poor (15/100); formability poor (20/100).
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. D1 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with D1
Is D1 easy to machine?
Machine only in the annealed state with rigid setups, sharp carbide or coated tooling and modest speeds; after hardening it is a grinding/EDM-only material (leave 0.2–0.4 mm grind stock).
Can D1 be welded?
Not a structural weld alloy — repair-weld only with matching high-Cr filler, preheat 400–500 °C, keep interpass temperature, then re-temper immediately to avoid quench cracks.
Can D1 be formed, bent or molded?
Hot work 900–1050 °C with slow furnace cooling; anneal 850–870 °C then harden 980–1010 °C, air or plate quench, double temper 150–200 °C (or 500–540 °C for secondary hardening) with size change under ~0.05 %.
D1 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 |
|---|---|---|
| Clower than D2 (1.4–1.6 %) | 0.85 – 1.1 | 1 |
| Cr | 11 – 13 | 12 |
| Mo | 0.7 – 1.2 | 1 |
| Voptional, max limit | ≤ 1.1 | 0.3 |
| Mn | ≤ 0.6 | 0.35 |
| Si | ≤ 0.6 | 0.3 |
| Niresidual | ≤ 0.3 | |
| Curesidual | ≤ 0.25 | |
| Wresidual/optional | ≤ 0.5 | |
| P | ≤ 0.03 | |
| S | ≤ 0.03 | |
| Fe | balance |
What surface finishes work on D1?
Takes a good mirror polish at 58–62 HRC; protect with oil, black oxide, hard chrome, nitriding or PVD TiN/CrN — the 12 % Cr is not enough to prevent rust in storage.
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
Equivalent designations
Standards and trade names that resolve to Steel D1 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- T30401
How much does D1 cost?
D1 is a standard-cost steel ($$), cheaper than about 71% 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.
D1 — frequently asked
What is D1 used for?
D1 is typically used for blanking dies, forming dies and thread rolling dies. In short: D2-class wear resistance; air-hardening long-run die steel; grind-only when hardened.
What is the yield strength of D1?
D1 has a typical yield strength of 420 MPa (60.9 ksi) and a tensile strength of 760 MPa (110 ksi) — weaker than 53% of steel grades. Strength varies by condition: see the 6 listed tempers.
Is D1 easy to machine?
Not especially — machinability is rated fair (35/100, worse than 84% of steel grades). Machine only in the annealed state with rigid setups, sharp carbide or coated tooling and modest speeds; after hardening it is a grinding/EDM-only material (leave 0.2–0.4 mm grind stock).
Can D1 be welded?
Not readily — weldability is rated poor (15/100). Not a structural weld alloy — repair-weld only with matching high-Cr filler, preheat 400–500 °C, keep interpass temperature, then re-temper immediately to avoid quench cracks.
What surface finishes work on D1?
Takes a good mirror polish at 58–62 HRC; protect with oil, black oxide, hard chrome, nitriding or PVD TiN/CrN — the 12 % Cr is not enough to prevent rust in storage.
Can D1 be formed, bent or molded?
Hot work 900–1050 °C with slow furnace cooling; anneal 850–870 °C then harden 980–1010 °C, air or plate quench, double temper 150–200 °C (or 500–540 °C for secondary hardening) with size change under ~0.05 %.
What is the maximum service temperature of D1?
D1 is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between D1-A and D1 QT-CRYO?
A is the default condition — standard mill-supplied condition for machining the die before hardening. QT-CRYO: use where residual austenite must be eliminated for size stability (gauges, precision punches). Yield strength is 420 MPa in A versus 1,850 MPa in QT-CRYO.
How much does D1 cost?
D1 is a standard-cost steel ($$), cheaper than about 71% 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 A681 Standard Specification for Tool Steels Alloy — ASTM International (2022)
- SAE J437/J438 Tool and Die Steels — SAE International (2007)
- ASM Handbook Vol. 1: Properties and Selection — Irons, Steels, and High-Performance Alloys (Tool Steels) — ASM International (1990)
- Tool Steels, 5th ed. (Roberts, Krauss, Kennedy) — ASM International (1998)
- GB/T 1299 (Cr12MoV / Cr12Mo1V1) — SAC / (2014)
- Cold-work tool steel D2/1.2379 datasheets (Böhler K110, Uddeholm Sverker 21) — voestalpine / Uddeholm (2022)
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.