A review of research into the role of guide pads in BTA deep-hole machining

A review is made of the literature dealing with the role of the guide pads in the boring trepanning association Heller (BTAH) deep-hole machining process. The link between processing and performance and the burnishing action of the guide pads is examined. This burnishing action which has previously been described as a finishing operation is in fact an extremely abusive process. It is shown that the area of guide pads in contact with the cut surface is at best only 1.2% of their projected surface area during burnishing. Also, no lubricating film can exist at the front of the guide pads.