This study deals with the trial for improvement of chip controllability in turning with selective laser heat treatment for workpiece. Selective heat treatment for carbon steel JIS S45C was carried out with Nd:YAG laser which could be transmitted through an optical fiber and shows higher absorption rate against carbon steels than CO2 laser. In turning of these selective laser heat threatened carbon steel, the chip form changed regular curl from irregular curl and chip breakability was improved compared with non-laser treated carbon steel. Surface roughness was obviously smaller comparing with non-laser treated carbon steel. Especially in the case that the depth of cut was larger, the surface roughness was smaller. As for cutting force, the principal force was slightly smaller, but the thrust force and feed force were almost the same. The cutting temperature was slightly lower. The tool wear was almost same as that in the case of non-laser treated carbon steel.
