Due to introducing robots to industrial production lines, it is expected that the productivity is increased, labor costs are reduced, and regular production is kept. At present, however, dexterity embedded into the robots is much inferior to skills of human beings. To improve the dexterity, we investigate robotic assembly of fixtures used in the production lines. To assemble the fixtures, we use a 4-finger 12 d.o.f. hand with a camera on the palm. In this paper, we investigate a grasp and insertion task of a bolt to a hole. And we investigate a grasp and insertion task of a slide unit to another slide unit. In these tasks, uncertainty of grasping by the hand occurs. To overcome the problem, we utilize the information of a 6-axis force sensor equipped in the robot wrist and the camera image.