The statistical study shows that there are some relations between the electrical parameters and the machining quality in electrical discharge machining (EDM). In order to control the cylindricity error of small hole machined by EDM

it is very necessary to study the relations between the electrical parameters and the cylindricity of small hole by technology experiments. In the course of studying

a measurement of multiple sections by cartesian coordinate is proposed

and then the cylindricity quantitative evaluation of hole is achieved. Based on the method above

an orthogonal experiment is used

and the effect of some main electrical parameters (voltage

current

pulse width

inter pulse and tool-lifting) on cylindricity of small hole is studied. The results indicate that pulse width affects cylindricity most distinctly

the voltage is secondary

and the effect of rest parameters is weak. The discharge parameters combination is achieved to purchase the least cylindricity error.