When clamping a straight shank milling cutter with a collet, if the chuck design is unreasonable, it is easy to drop the knife. In practice, we let the ratio of the two cones (see figure) of the chuck, the radial runout of the chuck is controlled at 10 ~ 20μm, so that the milling precision and the life of the milling cutter are extended. The collet has a unitary structure, and the flap is composed of two cones of different lengths and six elastic grooves.
Feton Corporation , https://www.ultraplantled.com