Guide · High Performance Metals
Böhler tool steel grades: a technical guide.
BÖHLER is the special- and tool-steel brand of voestalpine's High Performance Metals division, produced primarily at the Kapfenberg site in Austria. This guide covers the most widely used BÖHLER tool steel grades — cold-work, hot-work, powder-metallurgy stainless and additive-manufacturing powders — with typical composition, hardness and applications.
How BÖHLER grades are classified
BÖHLER uses single-letter prefixes to indicate the steel family: K for cold-work tool steel, W for hot-work tool steel, M for plastic-mould steel, S for high-speed steel and N for high-alloy special steel. The MICROCLEAN suffix marks third-generation powder-metallurgy grades, and ISOBLOC / ISODUR denote forged blocks with isotropic properties.
BÖHLER K110
Cold-work tool steel (AISI D2 equivalent)Typical composition: ~1.55% C, 11.3% Cr, 0.75% Mo, 0.75% V
Working hardness: 60–62 HRC after hardening and tempering
Applications: Blanking and forming dies, shear blades, thread rolling dies, woodworking knives.
The workhorse high-carbon, high-chromium cold-work grade. Excellent wear resistance and good compressive strength at a moderate price.
BÖHLER K340 ISODUR
Cold-work tool steel (Cr-Mo-V)Typical composition: ~1.10% C, 8.3% Cr, 2.1% Mo, 0.5% V
Working hardness: 58–62 HRC
Applications: High-performance stamping and cold-forging dies, fineblanking tools, deep-drawing punches.
Designed as a tougher, less brittle alternative to K110 for high-load cold-work tooling.
BÖHLER W360 ISOBLOC
Hot-work tool steelTypical composition: ~0.50% C, 4.5% Cr, 3.0% Mo, 0.6% V
Working hardness: Up to 57 HRC
Applications: Aluminium and zinc die-casting dies, forging dies, plastic moulds with high abrasive load.
Combines high hot hardness with good toughness — bridges classic hot-work and cold-work performance.
BÖHLER W400 VMR
Hot-work tool steel (premium H11 type)Typical composition: ~0.38% C, 5.0% Cr, 1.3% Mo, 0.4% V
Working hardness: 44–52 HRC
Applications: Aluminium die-casting dies, extrusion tooling, hot-forging dies.
Vacuum-arc remelted for very high cleanliness and isotropic properties — the standard for large die-casting blocks.
BÖHLER M390 MICROCLEAN
Powder-metallurgy stainless tool steelTypical composition: ~1.9% C, 20% Cr, 1.0% Mo, 4.0% V, 0.6% W
Working hardness: 60–62 HRC
Applications: Premium knife blades, plastic moulds for corrosive polymers, surgical instruments, wear parts.
Made by the third-generation Microclean PM route. Outstanding combination of corrosion resistance, edge retention and polishability — the benchmark grade for high-end pocket knives.
BÖHLER S390 MICROCLEAN
Powder-metallurgy high-speed steelTypical composition: ~1.64% C, 4.8% Cr, 2.0% Mo, 10.4% W, 4.8% V, 8.0% Co
Working hardness: Up to 70 HRC
Applications: End mills, drills, broaches, hobs and gear-cutting tools for difficult-to-machine alloys.
Top-tier PM HSS — exceptional hot hardness and wear resistance for high-performance cutting tools.
BÖHLER AMPO / L-PBF powders
Additive manufacturing tool-steel powdersTypical composition: Gas-atomised variants of M789, W360, M390 and maraging grades
Working hardness: Grade-dependent (up to ~54 HRC as-built)
Applications: Laser powder-bed-fusion conformal-cooled injection moulds, aerospace tooling, hybrid tooling repair.
Spherical gas-atomised powders qualified for L-PBF. Enables conformal cooling channels that cut cycle times in plastic injection moulding by 20–40%.
Böhler in additive manufacturing
voestalpine operates dedicated gas-atomisation lines for tool-steel and maraging powders used in laser powder-bed fusion. The most common AM grades are the corrosion-resistant M789 AMPO, the hot-work W360 AMPO and PM-stainless M390 AMPO. The main industrial use case is conformal-cooled injection moulds, where complex internal cooling channels — impossible to machine conventionally — shorten plastic moulding cycle times by 20–40%.
Where to go next
For the broader product context see the tool steel and high-speed steel entries, or read about the High Performance Metals division that owns the BÖHLER and UDDEHOLM brands.