Steel plate drilling should be light pressure, at any time pouring oil or water cooling.The impact of drilling concrete, to hold the drill, at any time will bring out the slag eye, to travel in a time not too long. Pay attention to the pipe line in the wall. Pay attention to the steel bar on the wall, it will drill body belt turn, wounding.
An angular grinder cannot grind a drill bit. You must grind a drill bit on a sander, and you are a layman, and you may not sharpen it even if you have it.There are so many fake twist drills, you can only buy them and buy more.
Grinding twist drill is the front edge of grinding, we do mechanical processing, the new twist drill must be polished, and then used. A mill can also grind, but it must be worn by those who can grind it. Percussive drilling and percussion drills are necessary for drilling. Twist drills for metal.
