Stainless steel Watch Case manufacturing for drilled hole for watch crown. you can see below 5 drills, each one has own function. first one drill is for fixed the position. then it goes to second one for drill through the hole on case. it goes to third one to make stage inside of hole. then it goes to 4th one for more precise inside construction, the last one is for water-resistance function. after the watch case out of machine, the worker put it on small drill to remove the unedged part from crown position. these works are very precise work and control by CNC machine. it sets by engineer acc to the technical drawing of watch cases.
These CNC machines are very popular for watch case manufacturing. such as the watch bezel and case itself, holes and lugs. after the CNC machine for case construction. then go to next step for finishing, like Full polished, Brushed, vertical brushed, Sandblasted, Polished and brushed mixture. it makes the finishing as per customer's request.
so you can see the case manufacturing is very very precise work. otherwise, it can't match the watch glass and Leather strap or Stainless steel bracelet.