Bit 8Mx1.25 suited me and did the job. Best $12.99 I could spend to drill and tap damaged threads on a car. I took my time (manually) to slowly let the beat do its work. Once the bit was solid, I moved the bit back and forth to loosen and remove the shavings. After passing, I gave up the beat with no problem. I threaded it with a matching threaded bolt and then an auto part. There were two places on the threaded portion of the drill where the drill had broken off. Both missing parts were on the trailing edge of the threads. You're trying to figure it out I'm not sure, but I expected the front edge of the faucet to be able to withstand more pressure. My bid was for body panels, not an engine. Metal chips are not a problem. Even broken bit fragments were not a problem in my case. Excellent value for money but the user might want to be aware that the material feels fragile. Many other buyers have had issues with more catastrophic bit failures. Take your time and stand behind you, but plan in case the beat doesn't work. The seller also responds VERY FAST AND REPLACES THE DAMAGED BIT. I will be increasing my overall rating for this transaction but the durability rating must remain at 3 stars.