Ordered these to drill alot of holes on a couple piano hinges I was installing on a storage bench I had made for our kitchen. They worked excellent except one little quirk. The spring loaded sleeve wouldn't always slide back down in place. That's the only reason for 4 stars. I would have to clean and adjust it back down with my fingers after each hole. Other than that these worked exceptionally. I had to drill around 100 holes and only had two that ended up off center which I attribute to user error and not a fault of the product itself. I would recommend these if your doing something like I had to do especially for the price. When I looked locally the bits were around 10 bucks each. So this in my opinion was definitely worth it. They seem well made other than the weak spring. Although I can't attest to how they would hold up to hard everyday use. I saw several reviews saying the bits would break so I tried to be gentle and had no problems. Overall I'm fairly happy with these.

I haven't used these bits yet but already surprised, good quality, well built quality case, well pleased, well worth the money

These self-centering drill bits came with the case and items shown in my photo. They work fine (so far) and appear to be good for a woodworking hobbyist and/or lighter duty work. A professional woodworker or cabinet shop would probably want to spend more money for a higher grade and more robust set.

I noticed other reviews commenting on the lead-in chamfer. (some indicated no chamfer on bits they received). As shown in my photo, mine came with a chamfer of approximately .04 inch x 45 deg's. I would prefer a slightly larger chamfer to help guide the outer shell of the bit into the hinge hole. HOWEVER, it's important to keep in mind the thickness of the material you are trying to center the hole within. For smaller diameter bits the matching item (such as leaf of a hinge) will be rather thin. Therefore, if the chamfer was much larger it could allow the shell to move around within the hole in the leaf (or other thinner gauge material). Another way to describe this concern is that a larger chamfer creates a smaller outside diameter on the shell that must match with the inside diameter of the hole being aligned. This could create inaccuracy in the self-centering. I was able to keep the shell in the hole with the existing small chamfer, so my view is the current profile is reasonable.

Based on the very strong reviews for this set of self-centering hinge drill bits I decided to purchase it and not the much more expensive Snap-on self-centering hinge tapper bit set (which has fewer bits). The bit assemblies are made of what looks like heavily chromed steel that is not likely to rust. It also centers the bits for perfect on-center holes (really important for setting hinges accurately). One slight problem was that the hole in the spring-loaded tip, through which the bit passes, was not quite centered on one of the 9/64 bit assemblies (it comes with two of the 9/64 size). I sent a photo of the off-center hole to Werkzeug and requested a replacement 9/64 bit assembly. I got an immediate (that day) response from the company with an apology. They asked me to verify my shipping address and the next day I received a message saying they were sending me a complimentary set and included an image of the shipping paperwork! The new set is perfect and now I am rich in self-centering hinge tapper drill bits. This is a small, young company that is eager to satisfy customers and improve on anything necessary. I strongly recommend them.
For the record, this is the first review I've ever written for any product.

I ordered the following item from Amazon on June 6th, 2019 and received them June 8th.
Werkzeug Self Centering Hinge Tapper Core Drill Bit Set for Woodworking, Adjustable Door Window Drill Bits with 1 Hex Key & 8 Replacement Drill Bits (5/64" - 1/4"), 16 Pieces
Looking them over they appeared to be well manufactured and of good quality. This is not something I use every day but when I need a hole properly placed this is what I use. Two days later it was time to give them a try. When I removed the 5/64" bit the drill bit fell out. I put it back in and took the Allen Wrench they supplied and went to tighten the set screw. The set screw would not budge and in fact twisted the Allen Wrench. I sent an email to the customer service department of Werkzeug which the address was found in a "Thank You" card enclosed with their product. I simply stated my problem and hoped for a response.
When I opened my email the following morning a reply was waiting. This is what I received"¦
Hi Jim,
Have a nice day!
Thanks for shop in our store. We are terribly sorry to hear the product you received is defective, and we would like to send a new one for you or arranged a fully refund without return. We are in continually improving our products and services.
Meanwhile, we also welcome you to post a shopping experience so that others can benefit from your experience. As a growing business, we know how scare time can be, so we especially appreciate your time and input.
I am truly sorry for the trouble that we give you. Please let me know your opinion.
Looking forward to hearing from you.
Sincerely,
Werkzeug VIP Customer Service
What more can you hope for??? I am very pleased with their product as well as the prompt and courteous reply. I'm expecting my replacement part to arrive any day.