EDM石墨（电火花加工）主要用于加工各种形状复杂和精密细小的工件，例如冲裁模的凸模、凹模、凸凹模、固定板、卸料板等，成形刀具、样板、电火花成型加工用的金属电极，各种微细孔槽、窄缝、任意曲线等，具有加工余量小、加工精度高、生产周期短、制造成本低等突出优点，已在生产中获得广泛的应用，目前国内外的电火花线切割机床已占电加工机床总数的60%以上。
电(dian)(dian)火(huo)花加(jia)(jia)工(gong)(gong)(gong)是利用(yong)电(dian)(dian)极与工(gong)(gong)(gong)件(jian)之间的火(huo)花通电(dian)(dian)时，所产生的瞬时间的高(gao)温，去层(ceng)(ceng)层(ceng)(ceng)蚀(shi)除工(gong)(gong)(gong)件(jian)表(biao)面上材料的原理。电(dian)(dian)火(huo)花加(jia)(jia)工(gong)(gong)(gong)适用(yong)于高(gao)硬度(du)导电(dian)(dian)工(gong)(gong)(gong)件(jian)的加(jia)(jia)工(gong)(gong)(gong)。

EDM是在(zai)车(che)、磨、铣之后的流行的第四种加工方法。与传统(tong)铜电极相比，EDM用等静压石墨有如优点：

1.同体积石墨的价格仅为铜电极的25%。
2.石墨加工速度是铜电极加工速度的3-5倍，加工表面光滑。
3.加工精度高，易于抛光。
4.石墨的体密仅为铜电极的1/5，更适于制作大型电极。
5.做为(wei)电(dian)火(huo)花(hua)(hua)加工(gong)用电(dian)极时，期消(xiao)耗仅为(wei)铜电(dian)极的1/3-1/5，且火(huo)花(hua)(hua)油(you)分解(jie)碳化物被覆，补偿电(dian)极耗损。