07-03-2012, 06:57 AM
I have used professional Cogsdill roller burnishing tools for both I.D. and O.D. work. The applications were always steels. mostly 4140.
On the O.D. tools, the roller was a highly-polished narrow contact design. On the I.D. tool, is was a mutli-roll design that would remind you of a needle bearing.
In both cases the prep of the work was critical. You had to deliberately leave a very coarse finish in turning or boring, so as to leave higher "peaks and valleys" for the burnishing rolls to mash into one smooth surface. Lubrication with oils helped, as long as they had EP (extreme pressure) additives. Way lubes can work well. Feed rate is important too. If you feed too slow, you risk getting flaking and redepositing on the work. Feed too fast and you get thread-like feed marks.
It does take some experimentation to get it working consistent, but can be worth the effort.
On the O.D. tools, the roller was a highly-polished narrow contact design. On the I.D. tool, is was a mutli-roll design that would remind you of a needle bearing.
In both cases the prep of the work was critical. You had to deliberately leave a very coarse finish in turning or boring, so as to leave higher "peaks and valleys" for the burnishing rolls to mash into one smooth surface. Lubrication with oils helped, as long as they had EP (extreme pressure) additives. Way lubes can work well. Feed rate is important too. If you feed too slow, you risk getting flaking and redepositing on the work. Feed too fast and you get thread-like feed marks.
It does take some experimentation to get it working consistent, but can be worth the effort.