Electrical Discharge Machining (EDM) in Malaysia is widely used in mould making industries. Parts for automotive, defence and telecommunication industries are also other examples of the products produced. The process is based on removing material from a part by a series of repeated electrical discharges between a tool called electrode and the work piece with the presence of dielectric. The dielectric serves as transportation of removed particles, remains electrically nonconducting until the breakdown voltage is reached, reconditions the dielectric strength, increases the energy density in plasma channel and cools the electrode. This paper presents the machining of ASSAB 718HH work pieces with copper tool using EDM die sinking method. Three commercial EDM dielectrics; Kerosene, Novis and Amoil were tested and comparison between material removal rate (MRR), tool wear ratio (TWR) and surface finish (SF) are given. Through Pugh Method, result shows that ASSAB 718HH is best machined with Novis. © (2013) Trans Tech Publications, Switzerland.