High-speed tool steel round bar is a type of high-carbon, high-alloy solid round stock. Renowned for its exceptional red hardness (the ability to maintain high hardness at elevated temperatures) and high wear resistance, it serves as a core material for manufacturing various cutting tools and precision molds. High-speed steel (HSS) is a high-carbon, high-alloy steel composed of significant amounts of elements such as tungsten (W), molybdenum (Mo), chromium (Cr), cobalt (Co), and vanadium (V). It consists primarily of metal carbides (e.g., tungsten carbide, molybdenum carbide, or vanadium carbide) embedded in a steel matrix; the carbon content ranges from 0.7% to 1.65%, and the total alloy content reaches 10% to 25%.

Main Classifications of High-Speed Steel

Based on alloy composition, HSS is primarily classified into the following categories:
1. Tungsten-series HSS:e.g., W18Cr4V. These feature excellent red hardness and wear resistance but relatively lower toughness; they are classic, long-established steel grades.
2. Tungsten-molybdenum series HSS: e.g., W6Mo5Cr4V2 (M2). These feature fine, uniform carbides and superior toughness and thermoplasticity, making them the most widely used general-purpose high-speed steels today.
3. High-molybdenum series HSS: e.g., W2Mo9Cr4V2. These have high molybdenum content, with performance characteristics similar to the tungsten-molybdenum series.
4. Cobalt-bearing HSS: e.g., M35, M42. The addition of cobalt (Co) significantly enhances red hardness and overall hardness, making them suitable for machining high-strength, difficult-to-cut materials.
5. Powder metallurgy HSS (PM HSS): Produced via powder metallurgy processes, these feature extremely uniform carbide distribution and no segregation. They combine high strength with high toughness and are used for high-end precision tools.

Based on application, high-speed steel can also be categorized into general-purpose and special-purpose types.
1. General-purpose HSS: Primarily used to manufacture cutting tools for metal materials with hardness ≤300 HB (e.g., drill bits, taps, saw blades) and precision tools (e.g., gear hobs, gear shaping cutters, broaches). Common grades include W18Cr4V, W6Mo5Cr4V2, etc.
2. Special-purpose high-speed steels: These include cobalt-bearing high-speed steels and ultra-hard high-speed steels (with a hardness of HRC 68–70). They are primarily used to manufacture cutting tools for difficult-to-machine metals (such as superalloys, titanium alloys, and high-strength steels). Common grades include W12Cr4V5Co5 and W2Mo9Cr4VCo8.

In terms of physicochemical properties, high-speed steel is characterized by high hardness, high strength, good toughness, red hardness, wear resistance, heat resistance, and favorable processing characteristics. The metal carbides within the steel primarily contribute to wear resistance and strength, while the steel matrix primarily contributes to toughness and the ability to absorb impact and resist fracture.

Regarding production processes, there are four main methods for manufacturing high-speed steel: traditional casting, electroslag remelting, powder metallurgy, and spray forming. High-speed steels produced via these methods can achieve further improvements in their properties through heat treatment. The heat treatment process typically involves: forging/rolling → annealing → quenching → multiple tempering cycles.

Performance Characteristics of High-Speed Steel

1. High Hardness and Red Hardness: After heat treatment, the working hardness can exceed HRC 63, with some high-performance grades reaching HRC 68–70. They maintain high hardness even at operating temperatures of 600°C—a key advantage distinguishing them from other tool steels.
2. High Wear Resistance: The presence of abundant carbides (such as tungsten carbide and vanadium carbide) within the steel provides exceptional wear resistance.
3. High Strength and Good Toughness: Proper heat treatment allows for an optimal balance of strength and toughness, enabling the material to withstand the impact and vibration encountered during cutting operations.

Main Application Areas for High-Speed Steel

High-speed tool steel round bars are key materials for manufacturing the following products:
1. Cutting Tools: Drill bits, milling cutters, taps, reamers, broaches, gear hobs, gear shaping cutters, saw blades, etc.
2. Precision Dies and Molds: Cold-work dies, hot-work dies, stamping dies, screw-making dies, etc.
3. Other wear-resistant components include rolls, high-temperature bearings, and high-temperature springs.

The global high-speed tool steel market is currently experiencing steady growth, with powder metallurgy high-speed steel representing a key area of development. Domestically, companies such as Tiangong International have secured a leading position in the global market. When selecting products, it is essential to comprehensively evaluate steel grades, manufacturing processes (electroslag remelting vs. powder metallurgy), and suppliers, taking into account factors such as the material to be machined, cutting conditions, and budget constraints.

Different countries have different regulations on high speed tool steel round steel. The following are some common national standards

Chinese standard:
GB/T 9943，“High-speed tool steels” is a Chinese national standard for high speed tool steel round bars, which includes chemical composition, mechanical properties, and dimensional tolerances of high speed tool steel round bars.

British Standard:
BS ISO 4957 is a British standard, which is an international standard on high speed tool steel and knife steel, which includes the chemical composition and mechanical properties of different types of high-speed tool steel.

American standard:
ASTM A600 is a standard issued by the American Society for Testing and Materials, which regulates the chemical composition, mechanical properties, and dimensional tolerances of high-speed tool steel.

Japanese standard:
JIS G4403 is a specification for high speed tool steel in Japanese Industrial Standards, including the chemical composition and mechanical properties of high-speed tool steel.

Surface condition: Available in various finishes, such as black (hot-rolled/forged), bright (cold-drawn/ground), and silver bright (peeled and polished), to meet diverse processing requirements.

General-purpose steel
Steel grade: W18Cr4V (W18)
Hardness (HRC): 62–65
Bending strength (GPa): 3.0–3.4
Impact toughness (MJ/m²): 0.18–0.32
Hardness at 600°C (HRC): 48.5
Characteristics: Good strength and grindability (can be ground using standard corundum wheels); moderate heat resistance; poor thermoplasticity.
Main applications: Highly versatile; widely used to manufacture drill bits, reamers, taps, milling cutters, gear-cutting tools, broaches, etc.

High-performance steel
Steel grade: W6Mo5Cr4V2 (M2)
Hardness (HRC): 63–66
Bending strength (GPa): 3.5–4.0
Impact toughness (MJ/m²): 0.30–0.40
Hardness at 600°C (HRC): 47–48
Characteristics: High strength and good thermoplasticity; heat resistance and grindability are slightly inferior to W18Cr4V; can be ground using standard corundum wheels.
Main applications: Suitable for manufacturing hot-forming tools and tools subject to impact or with structurally delicate designs.

Steel grade: W14Cr4VMnRE
Hardness (HRC): 64–66
Bending strength (GPa): Approx. 4.0
Impact toughness (MJ/m²): Approx. 0.31
Hardness at 600°C (HRC): 50.5
Main applications: Cutting performance comparable to W18Cr4V; suitable for manufacturing hot-rolling tools.

Other Grade EN-1A, EN-3B,EN-8,EN-9,EN-16, E-18,EN-19,EN-24, EN-29B, EN-31, EN-32B, EN-36, EN-36C, EN-42J, EN-45, EN-47, EN-48A, EN-100, EN-111, EN-202, EN352, EN-353, EN-1117 Etc.

High Speed Steel (HSS), HCHCR  OHNS in Grade:-M2, M3, M35, M42, T-1, T-4, T-15, T-42, D2, D3, H11, H13, OHNS-01 EN52