High-speed dry machining (HSDM) technology must be developmental trend of mechanical manufacturing field. HSDM tests of hardened AISIH13 were performed with YW2,SEM and EDS were used for inspection of morphology and analysis of element,respectively,and tool wear mechanism was investigated.The results indicated that temperature gradient is essential reason of tool wear.The rake surface takes on irregular concave,adhesive wear is leading wear pattern， the relief surface presents small inclined plane,fatigue exfoliation is dominating.Meanwhile,oxidation reaction and element diffusion exist in rake and relief surface,too.
