Grinding wheels for external cylindrical grinding of metal, cemented carbide and industrial ceramics from Tyrolit – ceramic, CBN or diamond, for maximum precision and optimum cost-effectiveness.
External cylindrical grinding is one of the most important precision grinding processes in industrial manufacturing. It is the method of choice wherever cylindrical external surfaces need to be brought to the tightest dimensional tolerances and the highest surface finishes: when grinding camshafts and crankshafts, gearbox components, fuel injection components, turbocharger parts or rollers. Tyrolit offers grinding wheels for external cylindrical grinding of unalloyed and low-alloy steels, high-alloy steels, HSS, cast metals, cemented carbide and industrial ceramics — ceramic-bonded CBN tools, resin-bonded CBN and diamond wheels, as well as conventional high-performance ceramic wheels. The result depends not only on the tool itself, but also on the interaction between the grinding wheel, the machine, the cooling lubricant, dressing technology and process parameters — and this is precisely where Tyrolit’s application consultancy comes into play.
In external cylindrical grinding, two main processes are used, each requiring different tool designs. In plunge grinding, the grinding wheel plunges radially into the rotating workpiece and machines a limited area — typically for bearing seats, Crankshaft journals or cam profiles. Here, profile accuracy, service life and short cycle times are of paramount importance. Tyrolit offers electroplated CBN discs (POLARIS BASIC/PLUS) and ceramic-bonded CBN tools (GENIS 2) that are specifically tailored to these requirements. In roll grinding — a special application of external cylindrical grinding for cold and hot rolling mills — significantly larger wheel diameters and maximum process reliability over many grinding cycles are required. Tyrolit’s range includes product lines specially developed for this purpose, such as CSS ROLL STAR 2.0 and GENIS ROLL STAR.
The choice of abrasive is the most important decision in external cylindrical grinding. CBN (cubic boron nitride) is the right abrasive grain for steels, high-speed steel (HSS), cast metals and stainless steel: it is gentle on the workpiece, achieves very long tool life and is suitable for demanding precision components in the automotive and medical technology sectors. Diamond is used where CBN reaches its limits — with cemented carbide and industrial ceramics. For this application, Tyrolit offers resin-bonded diamond grinding wheels (VIB STAR Diamond), which guarantee consistently high cutting performance and a long service life even with the hardest materials. Conventional ceramic grinding wheels (CSS ULTRA, conventional ceramic external cylindrical grinding wheels) are a tried-and-tested, cost-effective choice for steel and high-speed steel (HSS) — with a wide range of applications on all standard cylindrical grinding machines.
The diameter is the key dimension determining the purchase decision for external cylindrical grinding, as it determines compatibility with the cylindrical grinding machine. The Tyrolit range covers a wide spectrum: conventional high-performance ceramic wheels (CSS ULTRA) are available in diameters from 400 to 1,065 mm and can therefore be used on standard machines as well as on large-scale systems for crankshafts. Cylindrical grinding wheels (CSS ROLL STAR 2.0) are available in diameters ranging from 600 to 1,100 mm with wheel thicknesses of 60–152 mm. CBN cylindrical grinding wheels (GENIS ROLL STAR) are manufactured in all standard sizes up to a diameter of 915 mm. Ceramically bonded CBN precision wheels (GENIS 2, GENIS 2-FT) are manufactured to order for specific applications — a typical example for passenger car crankshaft machining is a wheel with a diameter of 500 mm.
The type of bond fundamentally determines the grinding behaviour. Ceramically bonded CBN discs (GENIS 2, GENIS 2-FT) are characterised by a high-strength bond with optimum wetting of the CBN grain. Low bond volumes enable open, cool-grinding specifications with a long service life — the range extends from highly porous designs for delicate components to extremely hard coatings for extreme applications such as peel grinding. Resin-bonded CBN and diamond discs (VIB STAR CBN, VIB STAR Diamond) utilise the VIB STAR vibration-damping backing system, specially developed by Tyrolit, which absorbs vibrations and ensures consistent surface finishes. Electrolytically bonded CBN discs (POLARIS BASIC/PLUS) are custom-made and can be re-coated multiple times — targeted treatment of the main load-bearing zones allows service life and profile accuracy to be specifically enhanced. Conventional ceramic discs (CSS ULTRA) benefit from a new type of bonding system featuring innovative sintering technology: the abrasive grain is subjected to significantly higher dynamic loads without breaking off prematurely — the result is maximum profile retention with minimal wear and cool grinding without burn-off.
Tyrolit has been a system partner of the automotive industry and other precision-driven industries. Three product lines have proved particularly effective in this regard: GENIS 2 sets new standards with its ceramic-bonded CBN technology — the blue neutral zone protects the substrate and enables maximum grain utilisation. In practice, when grinding car camshafts, GENIS 2 delivers dressing cycles of 90 shafts compared with 70 for the competition, and reduces the cycle time from 136 to 65 seconds. CSS ULTRA is the conventional high-performance tool for external cylindrical and thread grinding: its unique microarchitecture, featuring innovative sintering technology, increases tool life by 50 per cent compared with standard tools when machining crankshafts. POLARIS BASIC/PLUS rounds off the range for plunge grinding — each wheel is individually manufactured, can be re-coated multiple times and is suitable not only for steel and stainless steel but also for nickel-based alloys, such as those found in turbocharger components. For the medical technology and precision mechanics Tyrolit also offers bespoke system solutions, developed in close collaboration with machine manufacturers and customers.
Tyrolit has been in business since 1919 and is one of the world’s leading manufacturers of grinding tools. What sets Tyrolit apart in external cylindrical grinding is its combination of tool quality and process expertise: application engineers support customers directly on site, develop bespoke system solutions and carry out process simulations at the company’s own test centre. Tyrolit works closely with machine manufacturers and university institutions to continuously develop grinding processes. With over 500 patents, the highest quality standards and a global presence in over 140 countries, Tyrolit is the reliable partner for demanding precision grinding tasks — from individual consultancy through to complete comprehensive system solutions from a single source.
