Customised open gears for your cement and mining needs

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Big benefits for your heavy-duty operations with our open gears

Open gears describe individual and matching geared parts that are not incorporated in a common casing. In the cement and mining industries, the term ‘open gears’ usually refers to the girth gear and pinion drives of horizontal mills, kilns or dryers

Final alignment of a pinion drive on a SAG mill

The classic open gear arrangement includes the main motor, an intermediate gear unit for speed reduction and the pinion, which meshes with the girth gear. Our standardised product range, in combination with individually-designed girth gears and pinions, allows us to supply a customised power train for your specific application.

Open gears to drive your mill or kiln

We have produced girth gears and pinions in our production facility in Milan, Italy for more than 50 years. Because of the high wear resistance and homogenous crystal structure, we prefer to manufacture fabricated girth gears with forged rim material – but we are not limited to it. We can also use cast steel or ductile cast iron according to your requirements.

Our comprehensive range of girth gears is complemented by the many different types of pinions we manufacture – and we ensure that our high-grade steel pinions fit perfectly with the girth gears. With the ideal combination of material, hardness and finishing, our open gears provide long service life and smooth operation for your heavy-duty applications – extending beyond cement and mining as required.

Based on your application, available space and other individual parameters, our open gear solutions power your equipment – giving you the maximum performance from your processes.


Comprehensive geared parts

As a supplier of a large range of products for heavy-duty industry, we own an impressive number of state-of-the-art gear cutting and grinding machines. Besides producing geared parts for our various gear units in the cement and mining industries, we can also manufacture individual geared parts and matching sets for your special needs.

Dimensional check of the toothing is an integral part of the grinding process

We have hobbing, grinding, shaping and milling machines at our disposal – allowing us to manufacture a full range of components for spur, helical and bevel gears. A machining centre for large components and our modern, precise measuring devices complete our extensive production capacity.
Production capacity
Type of gearing Module Max. diameter of workpiece (mm) Face width (mm)
Bevel gear milling Unlimited 3,100 Unlimited
Bevel gear shaping 10 - 30 2,000 350
Internal gear shaping 5 - 30 5,150 750
External gear shaping 5 - 30 5,000 750
Internal gear grinding 2 - 32 4,000 1,550
External gear shaping 2 - 32 3,200 600
Girth gear external hobbing 2 - 45 11,200 1,250
Girth gear internal hobbing 2 - 25 6,500 400

And with a wide network of partners that extend our manufacturing capabilities even more, our product range has no limits.


The total open gear package from one source

With our adaptable, robust machining capabilities and vast expertise, we can provide complete open gear systems that meet your requirements. Based on your specifications, we can manufacture toothed parts with spur, helical, double helical or other types of gears – giving you well-matched components with smooth operation.


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