Remove the cylindrical plastic cap in front of the motor. This will expose the hex of the drawbar. If you then look on the right side of the black metal plate the motor is mounted to on the right hand side, you will see a hole. The hole is there to lock the spindle when tightening the drawbar. The FIXING PIN is the part that goes into the hole to lock the spindle. A 3/16 or a 13/64 drill bit will also work by inserting the shank end into the hole. Do not overtighten the drawbar especially with collets and DO NOT run the mill with the drill bit (or fixing pin) still in the hole. That will almost guarantee stripping the gears. I didn”t get a fixing pin with my mill either. They may not provide it with the R-8 model; I don’t know. For most applications, the drawbar can be tightened by holding the tool with your hand. R-8 tools hold very well with moderate tightening.