By using Sumitomo's multi-bladed reamers, Bosch Rexroth has increased its reaming productivity by a factor of ten. A bottleneck in the production process has been eliminated and tool lives have been considerably increased.

Bosch Rexroth, located in Lohr am Main in Germany, produces hydraulic components of various types and sizes, which are used in industrial hydraulics, machine tools, presses, shutter controls as well as in power plant sectors and stage equipment. 

A challenge for the production is to guarantee process reliability in producing valve bodies because depending on the application they are manufactured of different cast iron materials as GGG or spheroidal graphite iron. Additionally inside you have a number of small bridges representing subsequent valve seats that are subjected to tight tolerances.

Bad conditions for a reamer considering that it is supposed to produce a cylindrical bore with a diameter of 49.97 mm, without center offset over the entire length and through all control brigdes. Both, the center offset and the cylindricity have tight tolerances and may differ only in the ?-range. It is a big challenge at a depth of overall bore of 220 mm.

So far the hole was rubbed with a single-fluted reamer, which was difficult to adjust and reached only relatively small amounts of state. The exchanging was time-consuming and dependent on the particular employee. When retracting the first parts were mostly rejects. The tool exchange was always associated with a relatively long production interruption. Under these conditions a harmonious and reliable production process is difficult to achieve. Rubbing process and machine became a time-determining manufacturing bottleneck.

When looking for solutions, different variants of reamers have been tried out - with moderate success. Then they found the innovative tool system SR-Reamer of Sumitomo and invited Sumitomo's application engineers for testing. Immediately it showed remarkable time advantages compared to the standard rubbing. Sumitomo's SR-reamers are so called frequent-bladed reamers with a fixed working diameter. 

The aim of the conversion to eliminate a bottleneck in production and to become faster, has successfully been achieved at Bosch Rexroth. "We have become faster by a factor of ten," pointed out Dr. Tschannerl, the production manager. "The availability has increased significantly. Our savings with two upgraded diameters are already in a five-figures area. The return on investment was given within less than six months. With the active support by Sumitomo's application engineers, we have achieved results quickly. This was truly exemplary." Congratulations for the courageous step to re-try a current production with an innovative tool concept. Innovative products secure technological future as well as economic. If that is combined with an appreciable increase in productivity, the success is extensive.