Steel D5
AISI/SAE D5 · UNS T30405
D5 is the cobalt-bearing member of the D-series high-carbon high-chromium cold-work tool steels (UNS T30405), with cobalt added to raise hot hardness and wear resistance over the base D-type composition.
Reference datasheet — D5 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 ANN condition
D5 tempers and conditions
D5 is supplied in 5 conditions, soft to hard. ANN 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 |
|---|---|---|---|---|---|---|
ANNDefault Annealed | Standard as-supplied stock condition: soft enough to turn, mill and drill before hardening. | 450 | 760 | 14 | 235 HB | — |
Hardened & tempered 55–57 HRC | Choose when chipping of thin sections or shock loading is the failure mode rather than abrasion. | 1,600 | 1,900 | 2 | 56 HRC | — |
Hardened & tempered 58–60 HRC | The workhorse working hardness: balanced wear resistance and toughness for blanking dies and shear blades. | 1,800 | 2,100 | 1.5 | 59 HRC | 21 W/m·K |
Hardened + deep cryogenic + double temper, 61–63 HRC | Sub-zero treatment converts retained austenite for maximum dimensional stability and wear life in precision dies. | 1,900 | 2,050 | 1 | 62 HRC | 2.5 % IACS |
Hardened & tempered 60–62 HRC | Pick for long-run abrasive blanking, thread rolling dies and forming rolls where chipping risk is low. | 1,950 | 2,250 | 1 | 61 HRC | — |
What is D5?
D5 is the cobalt-bearing member of the D-series high-carbon high-chromium cold-work tool steels (UNS T30405), with cobalt added to raise hot hardness and wear resistance over the base D-type composition. It is bought as annealed bar, plate and blanks at about 235 HB (760 MPa tensile, 450 MPa yield) and heat treated to 55–62 HRC, with a cryogenic condition available. The limits are low machinability (score 30), very poor weldability (score 18), a service ceiling near 200 °C and only modest corrosion resistance. D2 is the nearest alternative when cobalt-level hot hardness is not required. D5 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). D5 has a yield strength of 450 MPa (65.3 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 52% of steel grades. Elongation at break is 14% and the elastic modulus is 210 GPa (30.5 Msi).
What is D5 used for?
- cold extrusion dies
- heavy blanking dies
- high-wear forming tools
Advantages
- Good corrosion resistance — 25/100, better than 92% 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
- High embodied carbon — 2.9 kg CO₂/kg, worse than 91% of steel grades
D5 properties
Typical room-temperature values for D5-ANN; bars are the position among steel grades.
Physical3
D5 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
D5 has a yield strength of 450 MPa (65.3 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 52% of steel grades. Elongation at break is 14% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
D5 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 10.5 µm/m·K (5.83 µin/in·°F).
Electrical3
D5 conducts electricity at 2.7 % IACS, worse than 96% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (25/100), better than 92% of steel grades.
Sustainability4
Producing a kilogram of D5 takes about 36 MJ of energy and emits 2.9 kg of CO₂ — more than 89% of steel grades. Typical recycled content is 35%.
Manufacturability8
D5's machinability is poor (30/100, worse than 89% of steel grades); weldability poor (18/100); 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. D5 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with D5
Is D5 easy to machine?
Machine only in the annealed condition with rigid setups, low speeds and carbide or coated-carbide tooling; hardened parts require CBN turning, grinding or EDM.
Can D5 be welded?
Poor weldability — preheat 400–500 °C, use matching or high-alloy filler, weld hot, then re-temper immediately to avoid cracking; repair welding only.
Can D5 be formed, bent or molded?
No cold forming; hot forge 900–1050 °C with slow furnace cooling, then full spheroidize anneal at ~870 °C to prevent cracking.
D5 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 |
|---|---|---|
| Cforms Cr-rich M7C3 carbides | 1.4 – 1.6 | 1.5 |
| Cr | 11 – 13 | 12 |
| Coraises hot hardness / temper resistance | 2.5 – 3.5 | 3 |
| Mo | 0.7 – 1.2 | 0.9 |
| Voptional, grain refinement | ≤ 1 | 0.5 |
| Mn | ≤ 0.6 | 0.4 |
| Si | ≤ 0.6 | 0.35 |
| Niresidual | ≤ 0.3 | |
| Curesidual | ≤ 0.25 | |
| P | ≤ 0.03 | |
| S | ≤ 0.03 | |
| Fe | balance |
What surface finishes work on D5?
Grind with soft, free-cutting wheels to avoid grinding burn; finish with nitriding, black oxide or PVD coating — mirror polish limited by coarse eutectic carbides.
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 D5 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- T30405
How much does D5 cost?
D5 is a premium-cost steel ($$$), cheaper than about 51% 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.
D5 — frequently asked
What is D5 used for?
D5 is typically used for cold extrusion dies, heavy blanking dies and high-wear forming tools. In short: cobalt-bearing D-series grade; maximum cold-work wear resistance; machine before hardening.
What is the yield strength of D5?
D5 has a typical yield strength of 450 MPa (65.3 ksi) and a tensile strength of 760 MPa (110 ksi) — stronger than 52% of steel grades. Strength varies by condition: see the 5 listed tempers.
Is D5 easy to machine?
Not especially — machinability is rated poor (30/100, worse than 89% of steel grades). Machine only in the annealed condition with rigid setups, low speeds and carbide or coated-carbide tooling; hardened parts require CBN turning, grinding or EDM.
Can D5 be welded?
Not readily — weldability is rated poor (18/100). Poor weldability — preheat 400–500 °C, use matching or high-alloy filler, weld hot, then re-temper immediately to avoid cracking; repair welding only.
What surface finishes work on D5?
Grind with soft, free-cutting wheels to avoid grinding burn; finish with nitriding, black oxide or PVD coating — mirror polish limited by coarse eutectic carbides.
Can D5 be formed, bent or molded?
No cold forming; hot forge 900–1050 °C with slow furnace cooling, then full spheroidize anneal at ~870 °C to prevent cracking.
What is the maximum service temperature of D5?
D5 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 D5-ANN and D5 HT60-62?
ANN is the default condition — standard as-supplied stock condition: soft enough to turn, mill and drill before hardening. HT60-62: pick for long-run abrasive blanking, thread rolling dies and forming rolls where chipping risk is low. Yield strength is 450 MPa in ANN versus 1,950 MPa in HT60-62.
How much does D5 cost?
D5 is a premium-cost steel ($$$), cheaper than about 51% 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 (2015)
- SAE J437/J438 — Tool and Die Steels — SAE International (2015)
- 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)
- High-carbon high-chromium cold-work tool steel datasheets (D-series) — Böhler / Crucible / Hudson Tool Steel (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.