Bushings (sleeves) with oil grooves are parts made of high hardness material (52 - 60HRC) and work in high pressure environments. The oil grooves are specially designed coolant channels on the inner cylindrical surface of the bushings to provide lubrication and cooling for the mechanical members. Currently, in order to machine these grooves in holes, mechanical cutting methods such as: turning, broaching, slotting... can commonly used. The disadvantages of these conventional methods are low productivity, low accuracy and the product quality depend heavily on worker skills. In this study, electrochemical machining method is used to machine oil grooves to achieve a high productivity and quality with a reasonable cost. This article presents the calculation and experimental selection of main parameters when designing and manufacturing electrochemical cathodes. Through calculations and experiments, based on existing equipment conditions, the article has determined a reasonable set of technological parameters for machining oil grooves: electrode gap = 1mm
flow pressure P = 6at
NaCl 11%
machining time t = 125s and Im = 70A.