The drill bit on the small stem bent while it was only the 2nd time I used it and the 1st time on metal to make a hole in an electrical panel with a 1.2mm sheet. I have never seen a drill bit bend so much before. It should have broken if it were made of better material and not bent. I have opened over 500 holes in panels with Bosch hole saws and I have never had such a problem. I only changed the drill bits due to wear.

I have it for 1 year. I have made a total of 4 or 5 holes with the large one, only in wood, never in iron. Yesterday I tried to make 2 more holes in wood (melamine, to be exact) and the second one was extremely difficult. I noticed that the drill bits were very worn out. Generally, I was careful not to overheat it while drilling melamine. It's a waste of money, get a better brand.