Mandrel bars
Deutsche Edelstahlwerke GmbH: Global partner of the tube industry.
When rolling seamless tubes, a pre-pierced steel billet is rolled over a mandrel bar by grooved rolls in a stretch reducing rolling process to produce a tube or a tube blank. The mandrel bar determines the shape of the inner tube surface.
36.3 million (30.7%) of the 118 million tonnes of steel tubes produced worldwide in 2007 were manufactured by seamless hot rolling.
Expert forecasts hold the promise of good prospects for the future.
Deutsche Edelstahlwerke supplies mandrel bars to virtually all producers of seamless tubes. The company is optimally equipped for the job, having an RF 70 - currently the largest forging machine - and a modern rolling mill, as well as straightening and machining units for the long product "mandrel bars". Mandrel bars are manufactured with lengths of up to roughly 26 m and production diameters of currently up to a maximum of 280 mm.
Deutsche Edelstahlwerke provides mandrel bars made of general-purpose hot work steels and special steel grades. Tailored to the different tube rolling methods and designed to suit the individual stresses, they are available in the following versions:
- Finish-machined and chrome-plated to customer drawings
- Finish-machined and oxidised to customer drawings
- Pre-machined, i.e. quenched and tempered, peeled