When I used it for 4.5 t SS, the center drill broke during the second drilling. I attempted to cut without pilot holes, but could not it? However, it does not say that the pilot hole is necessary in the instruction manual. The use environment is an upright drilling machine, the rotation speed should be within the proper rotation speed of the manual, the feed is manual, so it should not have been exerted force. It will not be a job if you break this soon. I am sorry just because it was a product that can expect an improvement in work efficiency.
It was used for correcting the hole position of the finished product of paint completion. The cutting ability of the specification was 13 t with an electric drill, but 16 t was possible if it was a low speed drill. It was very useful for fixing completed products as much as possible without damaging them. Since it was used for only one hole processing, there is no chipping of the chip, so the durability can not be evaluated.