So experience and my gut said to try this out due to the mostly positive reviews. For 17 bucks as opposed to $45+ from retail/hardware stores I figured it was worth the shot, especially since I only needed to make one hole. My mission was to drill a 2-1/2" hole in 3/8" porcelain tile for a shower diverter. No offense intended, but I've learned that some people base their reviews on their own inexperience, lack of skill or failure to follow directions. That does not result in an accurate product review - the product’s quality and performance is supposed to be reviewed and not be based on someone's inadequacies. Before purchasing an item, I run through many reviews to get a feel for the product. I've learned to disregard some reviews based on how they are written and by getting a feel of individual skill levels - whether it's for a tool or a blender. My method once again paid-off.Some denounced the hole saw because it didn't have a pilot bit, but a pilot bit would "walk" on tile and glass anyway and wouldn't serve much of a purpose. I created a guide out of a leftover piece of foam backer board and clamped it to the tile. It served as a drill guide and also helped keep a "dam" of water around the hole. I then had a hose nearby set on "mist" to supplement the water and clean-out the debris. I set this up over a 5 gallon bucket and began drilling. I used a variable-speed drill and squeezed the trigger just enough to give a pretty low RPM and applied fairly light pressure on the tile. Because I was using a guide, I didn't begin on an angle as you typically do with a diamond bit. After about 20 rotations, I felt a groove being made. At this point I knew it was working and continued drilling, cleaning out the hole with water spray every minute or two (the guide kept a pool of water in-between spray intervals). Within about 5 minutes the saw popped through. It probably would've been quicker but I stopped to examine the bit to see if other's claims of the diamond dust wearing smooth came true - but it didn't. I was surprised at how clean the hole was and that it only varied in size by 1/8" (in this type of work, that is considered acceptable - we're not assembling the space shuttle engine). So...I can almost guarantee failures were the result of not enough water, spinning the bit way too fast as if it was a high-speed bit, or leaning into it with too much pressure. I only needed it for a single hole but don't see why it wouldn't get through a few more. Now that being said, it seems as if it's designed and constructed for occasional use and is not meant to be a daily-use hole saw for a granite or tile contractor. The hole saw is ready to use as purchased - its arbor is welded to the bit and will fit in any standard 3-jaw drill chuck. It served my purpose well and I would recommend it for a few light-duty applications.NOTE: I purchased this item on Amazon for full price and have no affiliation to the seller. I try to write helpful, unbiased and insightful reviews because I also read reviews prior to making my own buying decisions. I notice many reviews lack helpful information, are not well written or give poor reviews based on not reading directions or failing to read the product details prior to purchasing. Writing valuable reviews helps pay it forward.
