Integral machine tool holders, modular machine tool holders, machine tool holders with balancing rings for high speed machining, balanceable and balanced machine tool holders, machine tool holders with built-in unbalance compensation, and machine tool holders for milling, drilling, threading, boring and turning operations; parts for machine tool holders, namely, collet chucks, hydro-expanding chucks, clamping units, flange mounts, actuators, nuts, spindles, chamfering rings, boring heads, ins...