"I got these recently so I cannot comment on the overall durability however to get this many bits at this price is excellent. I wouldn't mind if a few of them break. I have used them to drill through Iron gates around our church and they made the cut clean and effortless. Well chuffed with this purchase. I'll not need to hunt about for that 1 or 2 bits I've left in another case to find i had forgot 1 was blunt or broken."
"Got these as I go through bits like mad at times in my job, I like to sharpen drill bits but metal is so soft now days. Got this set and it's perfect for what I need. I filled my small bit set back up and keep it in my tool bag, while the metal box sits in my van or garage for when I need to re stock. Used it on all timbers and even the 2mm bit I put to the test of over 1200 holes in hard wood and still sat in my case now. Perfect. Good on metal too.. As you can see I couldn't recommend this set enough. Will last me many many years."