Different Aspects to Achieve the Hole Quality in Gun Drilling Machining

Abstract

The manufacturing industry is always trying to fulfill the requirement of various industries and developing facilities to manufacture the designed parts. Many applications for various industries demand for deep drill where the ratio of depth of the hole to the diameter is greater than twenty. Gun drilling, B.T.A. drilling and ejector drilling are the three drilling processes to make deep holes. In the gun drilling process the pressurized oil is fed through a longitudinal hole made in the drill body and chips are forced out through a longitudinal V-shaped flute to a chip box. It is desirable to obtain the accuracy and quality of hole obtained in the gun drilling process. Only few research articles are available to study the accuracy and quality of hole obtained in the gun drilling process. The quality of hole produced is measured in terms of quality achieved in the following parameters: diametral tolerance, roundness of the hole, surface quality, straightness, location and attitude. The various factors are responsible to achieve these qualities such as; rotational motion provided to work-piece and/or cutting tool, tool wear, misalignment, feed rate, oil flow, depth of hole, material hardness, etc. Different aspects of these factors to achieve quality are presented in this article. This article will be useful for researchers and manufacturers to get an overall view of obtaining good hole quality and accuracy and associated factors to obtain them in the better manner.