When we machine the bolt (Fig. 1), there are two 3.5mm wide symmetry grooves with a surface roughness of Rα1.6μm and a symmetrical groove of 180°. We use a floating clamping fixture to press on a set of V-shaped blocks. 8 workpieces, one knife can be used to mill one groove of 8 workpieces. When using, first loosen the screw 6 (Fig. 2), the briquetting block 4 drives the pressing block 5 to move up, and the big end of the eight workpieces abuts the positioning block 9 and then rotates the screw 6