It is best to mark the position before drilling. Punch a small mark with a central punch with a spring or draw the point to be drilled with a scriber, and choose one of the two methods according to the size of the hole to be drilled and the thickness of the metal.

When using the scriber, hold it firmly on the metal with your hands and move it down and left and right quickly. If a center punch is used, the drilled workpiece needs to be placed on a flat piece of metal, and then the center punch is placed on the workpiece and pushed down smoothly. The impact force of the center punch is large, so there is always a little metal scrap around it. However, it doesn't matter if the hole being drilled is quite large.

When drilling, the workpiece must be compacted. If it moves, it will rotate quickly with the drill bit. The location of the borehole is another major consideration. It is much easier to drill holes in a large area of uncut metal than in a small and neatly cut workpiece. If a central hole is needed, it is usually easier to handle and cut shapes around the hole. Usually, the workpiece on the workbench should be held in your hand. However, the metal drilled by hand-held cranes or electric drills will become very hot during drilling. In this case, the workpiece should be clamped with a piece of wood that can be held in the hand, or the drill bit should be put into oil or water to keep it cool during operation. If you want to drill a big hole, you can drill a small hole first and then gradually expand it, which is easier to operate.