Abstract: Described in the article is the application of EMERSON EV2000 Series frequency converter to the Ф 400mm band sawing machine incorporated with the Accu-Roll Precision Tube Rolling Plant of Pangang Group Chengdu I & S Co.,Ltd..For cutting round steel billets with hi-speed band sawing machine,the inlet roller conveyor motors are centralized-inverter controlled,while the outlet roller conveyor motors are frequency-changing controlled to ensure smooth transport and accurate positioning of the material.The main drive of the band sawer is dragged by means of converter and frequency-changing motor for bring about infinite speed regulation of the band saw as per billet size.Actual operation shows that the said series of frequency converter features appropriate running,desirable control effectiveness,low failure rate and moderate investment.