Robot is now expending their ability from simple repetitive tasks to complex assembling tasks for supporting human life activities and advanced manufacturing automations. Manufacturing automation needs more narrow tolerance to assemble parts than human life support. In manufacturing automation, insertion tasks are the most frequently used primitive tasks. It is simple but impossible assembling tasks for robots without calibrations by high precision sensory devices. Laser displacement sensors are more fast, robust, and high precision one than any other measuring devices. The high precision performance of laser displacement sensor makes robots use it as a calibrations and feature extractions device. This paper will address how to find out the hole position and insertion direction vector from the acquired point clouds. Experiments will show the automated precision insertion task of manipulators.