Screws and barrels melt and homogenize polymers in moulding and extrusion. Wear‑resistant steels and specialized screw designs ensure stable melt quality for PE, PP, ABS, PA and filled materials, supporting applications from injection moulding to pipe, film, and sheet extrusion.
Screws and barrels in plastifier units are core components in injection moulding and extrusion, responsible for melting, homogenizing, and conveying thermoplastic materials. The process begins as polymer pellets enter the feed zone, where the screw transports them forward, generating frictional and heating. In the compression zone, the channel depth decreases, increasing pressure and completing melting. The metering zone ensures consistent melt quality before injection or extrusion. Typical materials processed include PE, PP, ABS, PA, PC, PVC, and filled compounds such as glass‑fiber‑reinforced polymers. Screws are designed as standard three‑zone types or specialized barrier, mixing, and venting screws to improve melt uniformity and are typically manufactured from nitrided steels, bimetallic alloys, or tool steels including advanced powder metallurgical tool steels to ensure wear and corrosion resistance. Barrels are produced from nitrided or bimetallic materials featuring iron‑, nickel‑, or cobalt‑based liners to withstand abrasive fillers like glass fibers and corrosive polymers such as PVC or flame‑retarded compounds. Tooling considerations include heater bands, cooling channels, check valves, and wear sleeves. Applications span injection moulding, pipe extrusion, film and sheet production, recycling systems, and compounding lines, where consistent melt preparation is critical for product quality.
BÖHLER K110 is a 12% ledeburitic chromium steel and corresponds to material number 1.2379 (X153CrMoV12, D2). This tool steel combines the advantages of conventional 12% ledeburitic chromium steels with those of advanced tool steels. In the group of 12% ledeburitic chromium steels, BÖHLER K110 offers the best combination of wear resistance, compressive strength and toughness, for which reason it is used in virtually all cold work applications. Its advantageous tempering behavior with a pronounced secondary hardness maximum also enables the use of advanced coatings. This also makes BÖHLER K110 suitable for complex tools requiring a high degree of dimensional stability and shape stability.
Citește mai multBÖHLER K190 MICROCLEAN is a 12% ledeburitic chromium steel manufactured using powder metallurgy. This material has the highest alloy content of the group of 12% ledeburitic chromium steels. Due to its high vanadium content, BÖHLER K190 MICROCLEAN has a significantly better resistance to abrasive wear than the tool steels 1.2080, 1.2601, 1.2436 and 1.2379. At the same time, the powder metallurgical manufacturing process creates a uniform matrix with finely distributed primary carbides, which among other things contributes to the good toughness of the material. BÖHLER K190 MICROCLEAN is used in situations where tool steels like 1.2379 are insufficient in terms of wear resistance.
Citește mai multBÖHLER K340 ECOSTAR belongs to the group of conventionally produced 8% chromium steels. Compared to conventional 12% chromium steels, this conventionally smelted tool steel has better toughness, hardening response and higher adhesive wear resistance. This combination of high adhesive wear resistance and toughness also offers advantages for industrial knives subject to high stress. This grade is also used for stamping and cutting tools.
Citește mai multBÖHLER K340 ISODUR belongs to the group of 8% chromium steels. This tool steel is produced using the electro-slag remelting (ESR) process developed by BÖHLER. This re-melting technology ensures the lowest micro and macro segregation as well as excellent purity and uniformity of the material. Compared to conventional 12% chromium steels, BÖHLER K340 ISODUR offers significantly better toughness, hardening response and higher resistance to adhesive wear. This material is therefore used in virtually all cold work applications in situations where tool steels like 1.2379 are insufficient in terms of adhesive wear resistance and toughness. K340 ISODUR also features better machinability and reduces the risk of stress cracking during electrical discharge machining.
Citește mai multBÖHLER K360 ISODUR belongs to the group of 8% chromium steels. This tool steel is produced using the electro-slag remelting (ESR) process developed by BÖHLER. This re-melting technology ensures the lowest micro and macro segregation as well as excellent purity and uniformity of the material. The alloy composition with higher molybdenum and vanadium content makes BÖHLER K360 ISODUR even more wear resistant than BÖHLER K340 ISODUR. Compared to tool steels like 1.2379 (D2), this combination of better toughness and wear resistance offers significant advantages for punching and cutting tools.
Citește mai multBÖHLER K390 MICROCLEAN is a high-alloyed, high-performance cold work tool steel manufactured using powder metallurgy. This material has the highest alloy content in the group of cold work tool steels with high vanadium content. The high alloy content gives this material outstanding wear resistance. At the same time, the powder metallurgical manufacturing process creates a uniform matrix with finely distributed primary carbides. Among other things, this leads to good material toughness. BÖHLER K390 MICROCLEAN is a problem solver for applications requiring extremely high wear resistance and compressive strength.
Citește mai multBÖHLER K490 MICROCLEAN is a high-performance cold work tool steel with a balanced property profile, manufactured using powder metallurgy. This powder metallurgical tool steel offers an outstanding combination of high wear resistance, compressive strength, toughness and very good machinability. Thanks to the resulting flexibility, BÖHLER K490 MICROCLEAN is used in virtually all cold work applications, and in many cases this material is the first choice for newly developed tools. The commonly used hardening temperatures of BÖHLER K490 MICROCLEAN also enable shared heat treatment with popular cold work tool steels (1.2379, D2), making it very economical in terms of heat treatment.
Citește mai multBÖHLER M300 is a prehardened corrosion-resistant martensitic chromium steel that can be tempered to a higher strength due to its carbon content. Due to the alloying with chromium and molybdenum, BÖHLER M300 has very good corrosion resistance and good wear resistance and is therefore suitable for molds for processing chemically aggressive molding compounds (e.g. PVC).
Citește mai multBÖHLER M303 is a corrosion-resistant, martensitic chromium steel with very good toughness, corrosion resistance, good wear resistance and improved machinability and polishability. Compared to 1.2316, BÖHLER M303 has better homogeneity and is approved for food and beverage contact.
Citește mai multBÖHLER M303 ISOPLAST corresponds to a remelted BÖHLER M303 . The variation in the production route enables greater toughness and polishability thanks to higher purity and improved homogeneity. Also available as product variant BÖHLER M303HH ISOPLAST (high-hard variant).
Citește mai multBÖHLER M310 ISOPLAST is a corrosion-resistant, martensitic chromium steel which, through electroslag remelting and optimization of the chemical composition, has a good homogeneity and a balanced hardness-toughness-corrosion resistance ratio.
Citește mai multBÖHLER M340 ISOPLAST corresponds to a corrosion-resistant, martensitic chromium steel with improved wear resistance. This is ideal for the application area of glass fiber reinforced plastics. In addition, the BÖHLER M340 ISOPLAST is approved for food and beverage contact.
Citește mai multBÖHLER M368 MICROCLEAN is a corrosion-resistant, martensitic chromium steel produced by powder metallurgy. Due to the alloy concept and the production route, the steel has a high wear resistance, high corrosion resistance and high toughness. In addition, BÖHLER M368 MICROCLEAN is approved for food and beverage contact.
Citește mai multBÖHLER M390 MICROCLEAN is a corrosion-resistant, martensitic chromium steel produced by powder metallurgy. Due to its alloy design, this steel has very high wear resistance and good corrosion resistance. In addition, BÖHLER M390 MICROCLEAN is approved for food and beverage contact.
Citește mai multBÖHLER M398 MICROCLEAN is a corrosion-resistant, martensitic chromium steel produced by powder metallurgy. Due to its alloy design, this steel has good corrosion resistance and higher wear resistance compared to BÖHLER M390 MICROCLEAN.
Citește mai multBÖHLER N685 is a corrosion-resistant, martensitic chromium steel with a high carbon content and molybdenum and vanadium additives.
Citește mai multBÖHLER N690 is a corrosion-resistant, martensitic chromium steel with a high carbon content and the addition of cobalt, molybdenum and vanadium. BÖHLER N690 is also approved for food and beverage contact.
Citește mai multBÖHLER N695 is a corrosion-resistant, martensitic chromium steel with a high carbon content and added molybdenum.
Citește mai multBÖHLER W300 ISOBLOC is a 5% chromium steel and corresponds to material number 1.2343 (X37CrMoV5-1). Produced via the electroslag remelting process (ESR), this tool steel has very high hot toughness as well as good hot hardness and very good resistance against heat-checkings. The combination of these properties makes it a top performer in high- and low-pressure die casting as well as in closed-die and open-die forging. In addition, this material has very good polishability and is therefore also often used as a molding material for plastic injection molds.
Citește mai multBÖHLER W302 ISOBLOC is a 5% chromium steel and corresponds to material number 1.2344 (X40CrMoV5-1). Produced via the electroslag remelting process (ESR), this tool steel has very high hot toughness as well as very high hot hardness and a very good resistance against heat-checkings. The combination of these properties makes it a top performer in closed- and open-die forging as well as in high- and low-pressure die casting. In addition, this material has very good polishability and is therefore also often used as a molding material for plastic injection molds.
Citește mai multBÖHLER W360 ISOBLOC is a material produced by the electroslag remelting process (ESR), which has been specially adapted for use at high tool hardnesses in the range of 51-57 HRC. Although the steel can be classified as a 5% chromium steel, the increased carbon and molybdenum content coupled with state-of-the-art manufacturing technology ensures that BÖHLER W360 ISOBLOC still shows a very good toughness and an exceptionally good thermal resistance, even at high hardness levels. These properties make the steel the perfect choice for smaller components in the die casting sector (e.g., mold inserts, cores, core pins, ejector pins, etc.). The material also is frequently the preferred choice for closed-die and open-die forging tools due to its high wear resistance. Because of this excellent wear resistance and the high toughness, BÖHLER W360 ISOBLOC is also frequently used for cold work applications and as a molding material for plastic injection molds. The Steel also is available as powder material for metal-3D-printing under the brand name BÖHLER W360 AMPO.
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