Ideally use a drill press or clamp panel you are drilling 120mm hole in between 2 pieces of wood and drill at slow speed. Keep in mind the cutting tip speed of 60mm radius from center of drill is moving many, many times faster than cutting edges of a 13mm drill bit. The speed of saw teeth on 120mm hole saw are moving very fast even with drill turning over quite slowly.
What part of country are you located in?
What part of country are you located in?