Ridge, Ridge Go Away
Never Come Another Day

Rolling of rounds in the Bar Mill calls for special attention since these products are used in sophisticated applications by the engineering industry. Achieving proper quality in larger diameter rounds (from 80 mm to 140 mm) had always been difficult because of limitations like fluctuations in the bar temperature and the layout of Mill itself.

Another major problem faced was the formation of  a "ridge or fin" on the bar, which had to be ground to bring the rounds within the required tolerance limits. This not only led to a loss of metal, but also, unnecessary hold-up of the final product at the finishing end of the Mill.

The Mill staff in consultation with the Long Products Technology Group decided - "ye nahin chalega". The team identified that the roll pass design was the root cause of the malaise. The finishing pass design was modified. The conventional practice of introducing pass relief was withdrawn. The templates were made and the passes turned using the new templates.

The Roll Turning Shop completed the modification in all the passes within a record period of one week. Subsequent rolling of rounds from the month of May 2001 onwards has shown superior quality with respect to the dimensions. No ridge in the finished product - it is water under the bridge. Ting ting... tt ting