PURPOSE: To execute grinding of many kinds and a large quantity of objects by providing a pin for fixing parts and a drop preventive pin for parts and providing a through-rod allowed to pass through the drop preventive pin and a body for fixing these pins and the through-rod.

CONSTITUTION: A work fixing pin 2 is tightened and fixed to a fixed axis 1 by locking tools 3 such as a screw, a bolt, etc. This pin 2 is springy, moves in any direction of forward and backward direction and the right and the left, and plural pieces are arranged in the upper and the lower parts, etc. of plural axes of the axis 1. Also, a through-rod passes through a through-hole placed in the upper part of a drop preventive pin 5, passes through through-holes of all the pins 5 on the same axis and the same line of the axis 1, and thereafter, allowed to pass through a set screw 7 set to a plate 5 for fixing the through-rod fixed to the axis 1, and fixed by a butterfly nut 8. According to this constitution, a fixed object to be ground stands a grinding resistance in a rotary grinding machine, rotated without dropping, and the grinding working of a large quantity of various shape can be executed.