The aim of this experimental study is to evaluate the tool life of each cutting material used in dry hard turning of AISI H11, treated at 50 HRC. This steel is intended for hot work, is free from tungsten on CrMoV basis, insensitive to temperature changes and has a high wear resistance. It is employed for the manufacture of the moulds and inserts, module matrices of car doors and helicopter rotor blades. The tests of straight turning were carried out using the following cutting materials: carbides (H13A and GC3015), ceramics (mixed CC650 and reinforced CC670) and cermets (CT5015 and GC1525). Experimental results enable us to study the influence of machining time on flank wear VB of these cutting materials and to determine their lifespan for this cutting regime (depth of cut ap= 0.15 mm, feed rate f= 0.08 mm/rev and cutting speed Vc= 120 m/min). It arises that mixed ceramic (insert CC650) is more resistant to wear than cutting materials. Its tool life is 49 min and consequently, it is the most powerful.