The Assel tube mill imported from Mannesmann Demag Meer by Daye Steel Works is the first one with hydraulic quick-opening system, which has unique features in structure and a much wider product range compared with Transval three-roll tube mill.

• 大冶钢厂引进的西德曼内斯曼·德马克·米尔厂制造的第一台带液压快开系统的阿塞尔轧管机在设备结构上有别于特朗斯瓦尔三辊轧管机,在生产范围上有很大的灵活性。