Bornemann-Gewindetechnik manufactures threaded spindles for medical technology

Many of the threads used in medical technology are manufactured using the whirling process. In in-vitro diagnostic applications, screws and threaded spindles are used as machine parts in liquid handling systems or measuring instruments.

The whirling process has proven to be the ideal manufacturing process for these applications as the smooth surface often plays an important role in the threaded parts used. Another advantage is the possibility of producing threaded spindles with varying pitches, for example to compress liquids.

In the whirling process, a driven whirling ring works with a set of profile tools in the so-called envelope cut, as the workpiece rotates within this tool ring during machining. As the “envelope cut” starts at the outside diameter with a chip thickness (and chip depth) of 0, continuously increases to the calculated chip thickness (and chip depth or thread depth) and then exits the workpiece again at 0, a very “soft” cut is produced with a very smooth surface. The quality of the surface can be influenced by the feed rate in the whirling process. This means that extremely smooth surfaces or surfaces with microscopic smear pockets can be produced. Depending on requirements.

Bornemann-Gewindetechnik GmbH in Delligsen near Hildesheim has been manufacturing threads in all special shapes as well as turned and milled parts for 25 years with 40 employees on 3800m2 of company space. In addition to customers with industrial applications, Bornemann-Gewindetechnik’s customers also include many well-known manufacturers of in-vitro diagnostic applications, companies from the bioanalytics sector and manufacturers from the food industry.

All machinable materials can be used as the starting material for the production of threaded parts. The standard sizes for threaded spindles range from 10 to 180 millimetres in diameter and extend up to a length of 6 meters. In modern machining centers, dimensional tolerances of h6 can be maintained. With a spindle diameter of 100 millimeters, h6 would correspond to a tolerance of 99.978 to 100 millimeters, so that ball bearings could be properly mounted on it. The whirling process is used to achieve thread surfaces in grinding quality. The delivery time is 2 to 3 weeks after receipt of order.