Based on the very good reviews of this self centering swivel drill set I decided to use this instead of the much more expensive snap on self on. a set of nozzles for the centering joint (which has fewer nozzles). The bit assemblies are heavy chrome plated steel that is unlikely to rust. It also centers the bits for perfect center holes (really important for accurate hinge placement). A minor issue was that the hole in the spring loaded tip that the bit goes through was not quite centered on one of the 9/64 bit assemblies (comes in two sizes of 9/64). I sent a photo of the off center hole to tools and requested a replacement for the 9/64 bit. I received an immediate (same day) response from the company with an apology. They asked me to confirm my shipping address and the next day I received a message saying they would send me a free set and included a picture of the shipping documents! The new set is perfect, and now I'm rich with self-centering drill bits for cutting hinges. This is a small young company that strives to please customers and improve everything they need. I highly recommend them. For the record, this is the first review I've ever written for a product.