Steel SKD61
JIS SKD61 · EN 1.2344
SKD61 is the JIS G4404 5 % Cr-Mo-V air-hardening hot-work tool steel, essentially equivalent to AISI H13, DIN 1.2344 and 4Cr5MoSiV1.
Values for the Annealed condition
SKD61 tempers and conditions
SKD61 is supplied in 6 conditions, soft to hard. Annealed 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 |
|---|---|---|---|---|---|---|
AnnealedDefault soft annealed, ≤235 HB | Standard as-delivered condition for plate, block and bar; machine the cavity first, then harden. | 415 | 760 | 25 | 19 HRC | — |
Supplied ready to machine | For plastic-mould bases and holder blocks machined directly to final size without further heat treatment or distortion risk. | 1,050 | 1,250 | 14 | 40 HRC | 3.2 % IACS |
Quenched and tempered | Toughness-biased hardness band for die-casting dies, extrusion tooling and hot-forging inserts exposed to thermal shock. | 1,250 | 1,500 | 12 | 46 HRC | — |
Electroslag-remelted premium quality | Choose remelted SKD61/H13 (e.g. Orvar Supreme, W302 ISO-B) for large die-casting dies needing isotropic toughness and mirror polish. | 1,270 | 1,520 | 13 | 46 HRC | 3.2 % IACS |
Q&T core 44–48 HRC with gas/plasma-nitrided case | Surface treatment for extrusion dies and die-casting cores to resist erosion, soldering and abrasive wear; case is brittle so avoid sharp edges. | 1,300 | 1,500 | 9 | 46 HRC | 3.3 % IACS |
Low-temper, maximum hardness | Use only where wear/indentation resistance dominates and impact loading is low; toughness and thermal-fatigue life are reduced. | 1,650 | 1,950 | 8 | 53 HRC | — |
What is SKD61?
SKD61 is the JIS G4404 5 % Cr-Mo-V air-hardening hot-work tool steel, essentially equivalent to AISI H13, DIN 1.2344 and 4Cr5MoSiV1. It is supplied annealed at 215 HB (415 MPa yield, 760 MPa tensile, 25 % elongation) and used hardened and tempered to 52–54 HRC or pre-hardened at 38–42 HRC, also as ESR or nitrided stock, because it holds hardness and thermal-fatigue (heat-checking) resistance at 500–600 °C with low quench distortion; the continuous service temperature on file is 400 °C. With only 5 % Cr it is not stainless and needs rust protection and polish maintenance, hard-state cutting is limited to hard milling, grinding and EDM, and toughness falls as hardness rises, so avoid sudden thermal shock. SKD61 has a density of 7.8 g/cm³ (0.282 lb/in³), lighter than 87% of steel grades. It melts at 1,427°C (2,601 °F). SKD61 has a yield strength of 415 MPa (60.2 ksi) and a tensile strength of 760 MPa (110 ksi) — weaker than 56% of steel grades. Elongation at break is 25% and the elastic modulus is 210 GPa (30.5 Msi).
What is SKD61 used for?
- Aluminium and zinc die-casting dies
- Hot extrusion dies, mandrels and containers
- Hot forging die inserts
- Plastic injection mould cavities and cores
- Die-casting cores, ejector pins and sleeves
- Hot shear blades and hot punches
Advantages
- Polishes to a fine finish — 80/100, better than 97% of steel grades
- Ductile — tolerates forming and impact — 25%, better than 77% of steel grades
Limitations
- High embodied carbon — 2.8 kg CO₂/kg, worse than 90% of steel grades
- Poor heat conductor — 24.5 W/m·K (14.2 BTU/hr·ft·°F), worse than 89% of steel grades
- Low electrical conductivity — 3.3 % IACS, worse than 86% of steel grades
SKD61 properties
Typical room-temperature values for SKD61-Annealed; bars are the position among steel grades.
Physical2
SKD61 has a density of 7.8 g/cm³ (0.282 lb/in³), lighter than 87% of steel grades. It melts at 1,427°C (2,601 °F).
Mechanical14
SKD61 has a yield strength of 415 MPa (60.2 ksi) and a tensile strength of 760 MPa (110 ksi) — weaker than 56% of steel grades. Elongation at break is 25% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
SKD61 is rated for continuous service to 400°C (752 °F). It conducts heat at 24.5 W/m·K (14.2 BTU/hr·ft·°F), worse than 89% of steel grades. Thermal expansion is 11 µm/m·K (6.11 µin/in·°F).
Electrical3
SKD61 conducts electricity at 3.3 % IACS, worse than 86% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (20/100), better than 87% of steel grades.
Sustainability4
Producing a kilogram of SKD61 takes about 36 MJ of energy and emits 2.8 kg of CO₂ — more than 89% of steel grades. Typical recycled content is 35%.
Manufacturability6
SKD61's machinability is good (55/100, better than 62% of steel grades); weldability fair (35/100); formability poor (30/100).
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. SKD61 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with SKD61
Is SKD61 easy to machine?
Machine in the annealed state with carbide tooling and rigid setups; above ~45 HRC switch to hard milling with coated carbide/CBN, grinding or EDM (recover the white layer by stress-relief temper).
Can SKD61 be welded?
Repair welding only — preheat/interpass 350–450 °C, matching 1.2344-type filler, slow cool then temper 20–30 °C below the last tempering temperature.
Can SKD61 be formed, bent or molded?
Hot work at 1050–850 °C followed by slow cool and soft anneal at 850–900 °C; no meaningful cold forming. Harden 1000–1030 °C, air/vacuum or oil quench, temper twice (≥550 °C) for the target hardness.
Manufacturability
The process limits FabDigit's quote engine applies to SKD61. Design inside these and the part quotes instantly; outside them it routes to an engineer.
CNC machining
| Machinability | Fair55 / 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 |
SKD61 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 |
|---|---|---|
| CJIS G4404 SKD61; ASTM H13 allows 0.32–0.45 | 0.35 – 0.42 | 0.39 |
| Si | 0.8 – 1.2 | 1 |
| Mn | 0.25 – 0.5 | 0.4 |
| P | ≤ 0.03 | |
| S | ≤ 0.02 | |
| Cr | 4.8 – 5.5 | 5.1 |
| Mo | 1 – 1.5 | 1.3 |
| V | 0.8 – 1.15 | 0.95 |
| Niresidual | ≤ 0.25 | |
| Curesidual | ≤ 0.25 | |
| Fe | balance |
What surface finishes work on SKD61?
Takes a high mirror polish (best on ESR stock); protect with nitriding, hard chrome, or PVD CrN/AlTiN and always oil in storage since it is not corrosion resistant.
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 SKD61 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- EN / DIN / Werkstoff-Nr.
- 1.2344
How much does SKD61 cost?
SKD61 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.
SKD61 — frequently asked
What is SKD61 used for?
SKD61 is typically used for aluminium and zinc die-casting dies, hot extrusion dies, mandrels and containers, hot forging die inserts, plastic injection mould cavities and cores, die-casting cores, ejector pins and sleeves and hot shear blades and hot punches. In short: workhorse hot-work tool.
What is the yield strength of SKD61?
SKD61 has a typical yield strength of 415 MPa (60.2 ksi) and a tensile strength of 760 MPa (110 ksi) — weaker than 56% of steel grades. Strength varies by condition: see the 6 listed tempers.
Is SKD61 easy to machine?
Reasonably — machinability is rated good (55/100, better than 62% of steel grades). Machine in the annealed state with carbide tooling and rigid setups; above ~45 HRC switch to hard milling with coated carbide/CBN, grinding or EDM (recover the white layer by stress-relief temper).
Can SKD61 be welded?
With care — weldability is rated fair (35/100). Repair welding only — preheat/interpass 350–450 °C, matching 1.2344-type filler, slow cool then temper 20–30 °C below the last tempering temperature.
What surface finishes work on SKD61?
Takes a high mirror polish (best on ESR stock); protect with nitriding, hard chrome, or PVD CrN/AlTiN and always oil in storage since it is not corrosion resistant.
Can SKD61 be formed, bent or molded?
Hot work at 1050–850 °C followed by slow cool and soft anneal at 850–900 °C; no meaningful cold forming. Harden 1000–1030 °C, air/vacuum or oil quench, temper twice (≥550 °C) for the target hardness.
What is the maximum service temperature of SKD61?
SKD61 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.
What is the difference between SKD61 Annealed and SKD61-ESR?
Annealed is the default condition — standard as-delivered condition for plate, block and bar; machine the cavity first, then harden. ESR: choose remelted SKD61/H13 (e.g. Orvar Supreme, W302 ISO-B) for large die-casting dies needing isotropic toughness and mirror polish. Yield strength is 415 MPa in Annealed versus 1,270 MPa in ESR.
How much does SKD61 cost?
SKD61 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.
Can FabDigit make parts in SKD61?
Yes — SKD61 is available for CNC machining with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- JIS G 4404 Alloy tool steels (SKD61) — JSA (2015)
- ASTM A681 Standard Specification for Tool Steels Alloy (H13) — ASTM (2020)
- GB/T 1299 (4Cr5MoSiV1) — SAC (2014)
- ASM Handbook Vol. 1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- Uddeholm Orvar Supreme / Orvar 2 Microdized — Uddeholm (voestalpine) (2022)
- BÖHLER W302 / W302 ISOBLOC hot work tool steel — Böhler Edelstahl (2021)
- AISI H13 tool steel property record — MatWeb (2024)
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.