Steel SKD61 · temper · default condition
Steel SKD61 Annealed
Properties of the Annealed condition, compared with the other SKD61 tempers.
Standard as-delivered condition for plate, block and bar; machine the cavity first, then harden.
What is SKD61 Annealed?
SKD61 Annealed is SKD61 in the Annealed temper — standard as-delivered condition for plate, block and bar; machine the cavity first, then harden. SKD61 Annealed has a yield strength of 415 MPa (60.2 ksi) and a tensile strength of 760 MPa (110 ksi) — weaker than 55% of steel grades. Elongation at break is 25% and the elastic modulus is 210 GPa (30.5 Msi). SKD61 Annealed 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).
Advantages
- Polishes to a fine finish — 80/100, better than 97% of steel grades
- Ductile — tolerates forming and impact — 25%, better than 76% 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 87% of steel grades
SKD61 Annealed properties
Typical room-temperature values for SKD61 Annealed — 11 properties are specific to this condition; the rest are grade-level values shared by every SKD61 temper. Each bar shows where the value sits among the steel grades in FabDigit's library — further right is higher.
Physical2
SKD61 Annealed 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 Annealed has a yield strength of 415 MPa (60.2 ksi) and a tensile strength of 760 MPa (110 ksi) — weaker than 55% of steel grades. Elongation at break is 25% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
SKD61 Annealed 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 Annealed conducts electricity at 3.3 % IACS, worse than 87% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (20/100), better than 87% of steel grades.
Sustainability4
Producing a kilogram of SKD61 Annealed takes about 36 MJ of energy and emits 2.8 kg of CO₂ — more than 88% of steel grades. Typical recycled content is 35%.
Manufacturability6
SKD61 Annealed'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.
Other SKD61 tempers and conditions
SKD61 is also supplied in 6 other conditions. The full side-by-side table is on the SKD61 overview.
- AnnealedDefaultStandard as-delivered condition for plate, block and bar; machine the cavity first, then harden.415 MPa yield · 19 HRC
- Q&T 52-54 HRCUse only where wear/indentation resistance dominates and impact loading is low; toughness and thermal-fatigue life are reduced.1,650 MPa yield · 53 HRC
- NitridedSurface treatment for extrusion dies and die-casting cores to resist erosion, soldering and abrasive wear; case is brittle so avoid sharp edges.1,500 MPa tensile
- Hardened & TemperedHigher-hardness band for plastic moulds, shear blades and wear-critical hot-work tooling where thermal shock is moderate.1,470 MPa yield · 50 HRC
- ESRChoose remelted SKD61/H13 (e.g. Orvar Supreme, W302 ISO-B) for large die-casting dies needing isotropic toughness and mirror polish.1,270 MPa yield · 46 HRC
- Q&TToughness-biased hardness band for die-casting dies, extrusion tooling and hot-forging inserts exposed to thermal shock.1,250 MPa yield · 46 HRC
- Pre-hardened 38-42 HRCFor plastic-mould bases and holder blocks machined directly to final size without further heat treatment or distortion risk.1,050 MPa yield · 40 HRC
Working with SKD61 Annealed
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.
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.
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 | — |
SKD61 Annealed — frequently asked
What is SKD61 Annealed used for?
SKD61 Annealed 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 Annealed?
SKD61 Annealed has a typical yield strength of 415 MPa (60.2 ksi) and a tensile strength of 760 MPa (110 ksi) — weaker than 55% of steel grades. Strength varies by condition: see the 7 listed tempers.
Is SKD61 Annealed 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 Annealed 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 Annealed?
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 Annealed 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 Annealed?
SKD61 Annealed 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.
Can FabDigit make parts in SKD61 Annealed?
Yes — SKD61 Annealed 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. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.