Introduction
SKD61 steel is popular in Korea for a simple reason—it delivers strong performance without high costs. After years of supplying Korean die-casting and forging shops, we’ve seen how SKD61 helps factories cut tooling cost per part, extend die life, and keep production stable.
The steel handles heat well, resists thermal fatigue, and stays dimensionally steady after heat treatment. This means fewer early failures and less finishing work. Buyers also like its flexible sourcing—SKD61, H13, and 1.2344 offer similar performance, so teams can choose the best global price.With easy machining, reliable coatings, and well-known processing parameters, SKD61 gives Korean manufacturers a low-risk, cost-effective solution for most hot-work applications.
Why SKD61 steel remains popular in Korea
Three factors explain SKD61’s dominance in Korean hot-work tooling: shop-floor know-how, competitive cost, and local suppliers you can count on. Korean die shops pick this grade for 50–70% of their hot-work tool steel purchases. The steel gives you predictable results. You avoid the trial-and-error costs that newer premium alloys bring.
1. Cost-performance balance Korean factories trust
SKD61 costs 20–40% less per kilogram than premium ESR-remelted hot-work steels in Korea. Yet it gives 60–80% of their service life in standard aluminum die-casting work. Mid-volume auto parts suppliers run molds to 80,000–150,000 shots with proper heat treatment and nitriding. Premium grades reach 120,000–250,000 shots. But their higher material cost, longer heat-treatment cycles, and extended delivery times often cancel out the life gain.
Hot-forging shops see similar economics. SKD61 gives 1.0–1.5 times the life of older chromium hot-work steels. Material cost rises just 10% higher. This trade-off works for Korean forges focused on mid-cost output. They skip the upfront investment that premium alloys demand.
2. Known processing parameters cut risk
Korean machinists and programmers already know SKD61 well. Cutting data, EDM settings, and heat-treatment cycles have been refined over decades. Pre-hardened material at 30 HRC machines at 80–150 m/min cutting speeds with carbide tools. High-speed milling parameters come from years of fine-tuning.
Heat-treatment plants across Korea run standard quench-and-temper cycles for SKD61. Large die blocks 200–600 mm thick come out with little distortion or cracking risk. Less-familiar premium alloys need careful trial runs. This adds scrap cost and pushes lead times out.
Nitriding vendors stock proven recipes. Gas or ion nitriding at 500–530°C builds 0.10–0.30 mm case depth. Surface hardness hits 900–1,100 HV. No parameter development needed. Korean die shops get the same results batch after batch.
3. Supply-chain benefits in Korean industrial zones
Korean and Japanese suppliers stock SKD61 in wide size ranges—round bars 40–600 mm diameter and plates 25–300 mm thick. Lead time drops to 1–3 days in major industrial zones. Special grades take 1–2 weeks or more.
High inventory turnover keeps prices competitive. Korean distributors build their hot-work product lines around SKD61. It holds the largest domestic share in hot-work tool steel sales. Steady demand keeps stock available and prices stable.
4. Cost advantages of SKD61 steel
SKD61 steel saves you money in two ways. First, it extends die life. Second, it cuts tooling costs per part.
Proper tempering brings this hot-work tool steel to 50–52 HRC hardness. This hardness lets forging and die-casting tools run much longer than lower-alloy options. A Korean automotive shaft maker switched from H11 forging dies to SKD61. Die life jumped 30% under high-cycle conditions. Tooling cost per component dropped right away.
1. Lower per-shot costs: SKD61 resists heat-checking and thermal cracking. High-pressure die casting molds endure hundreds of thousands of cycles, reducing crack-related breakdowns, replacement costs, and unplanned downtime.
2. Material pricing & sourcing: Mid-range SKD61 is widely available. Equivalents like H13 or 1.2344 allow buyers to select the cheapest source, cutting material costs 15–20% in Asian factories without performance loss.
3. Lower machining & process costs: Optimized hard turning parameters (8,038 mm³/min removal, 0.96 µm Ra, 0.17 mm/rev feed) balance productivity, surface finish, and tool wear, reducing total die manufacturing costs beyond raw material savings.
4. Longer service life via coatings: Multilayer PVD coatings improve surface wear and heat-check resistance, extending shot counts, reducing fixture changes, maintenance, and overall operating costs in high-temperature die-casting production.
SKD61 delivers cost savings, consistent performance, and extended tool life through thermal stability, flexible sourcing, efficient machining, and coating strategies, supporting reliable, efficient, and economical die-casting and forging operations.
5. Performance in production of SKD61 steel
SKD61 delivers hardness between 44–52 HRC after proper heat treatment. Korean factories get the balance they need between toughness and wear resistance in hot-work tooling.
The steel reaches 52–54 HRC straight from the quench. Double or triple tempering at 520–600°C brings it down to the working range. Korean die shops temper at 540°C to hold 52 HRC. Maximum surface hardness matters? That’s the setting. They temper at 565°C to reach 48 HRC. Impact resistance counts more? Go with that. Charpy V-notch energy jumps from 10 J at 540°C to 18 J at 565°C. This shift cuts die breakage in high-shock forging jobs.
1. Dimensional stability: Heat-treat expansion only 0.07–0.08%, enabling tight tolerances and 15–25% less finishing labor for Korean mold shops.
2. Thermal performance: 24.3 W/m·K conductivity and 11.5–12.4 µm/m·°C expansion reduce thermal cracking; molds reach 420,000 shots before heat checks.
3. EDM machinability: Powder-mixed EDM boosts removal rate 20–40% and cuts tool wear 10–30%, allowing final-geometry machining without re-hardening.
4. Mechanical strength: 1200–1590 MPa tensile, 1000–1380 MPa yield, and 207 GPa modulus keep dies rigid under high clamping pressure.
The properties of SKD61 making it ideal for die casting, extrusion, forging, and high-temperature plastic molds. Korean automotive and industrial shops rely on it for engine blocks, profiles, forged parts, and plastic components, achieving long-lasting dies, precise shapes, and efficient production.
6. Typical Korean factory uses of SKD61 steel
Korean factories use SKD61 steel (STD61 under KS standards) in four main hot-work tooling areas. These include aluminum high-pressure die casting, aluminum extrusion, hot forging, and high-temperature plastic molding. Industry surveys show SKD61/STD61 makes up 50–70% of total hot-work tool steel tonnage that Korean mold and tool shops buy. Aluminum die casting and extrusion dies create this high demand.
1. Aluminum die casting: Used by Hyundai–Kia for engine blocks, housings, EV parts; SKD61 inserts sized 300–800 mm, full dies 500–3,000 kg.
2. Aluminum extrusion: SKD61 supports 150–500 mm dies for window frames, automotive profiles, heat sinks; ideal for multi-hole dies under thermal cycling.
3. Hot forging: Korean shops forge CV-joints, gears, crankshafts using 200–600 mm SKD61 blocks in 1,000–6,000-ton presses.
4. High-temperature plastic molds: SKD61 maintains hardness and accuracy near hot runners for PC, PBT, GF-PA parts like connectors and electronic housings.
SKD61 excels in these areas, maintaining hardness, dimensional stability, and thermal resistance. Korean automotive and industrial shops rely on it for engine blocks, profiles, forged parts, and plastic components, ensuring long die life and precise, high-quality production.
Conclusion:
After years working alongside Korean manufacturers, I’ve learned that success in tooling isn’t about chasing the newest premium grade—it’s about knowing your process inside and out. SKD61 gives Korean shops exactly that: predictable performance they can plan around, costs they can control, and supply chains they can trust. When your team understands the steel as well as the dies they build, you stop gambling on tooling and start building profit into every shot.