They fit the 3.5 Dremel saw. I was unable to find the blades anywhere else glad Tractor Supply had this package.

The US700 Ultra-Saw Kit contains a variety of saw blades capable of cutting wood, plastics, metal, and ceramics. The wood cutting blade US500 is constructed with a fine granular carbide cutting edge which I have found can cut a minimum width of .067in (1.7mm). The 3.9in. diameter will allow a maximum cutting depth of ~.75in (19mm). The metal and ceramic blades have a 3.5in diameter and will only permit a ~.55 depth of cut. The metal blade US510 will quickly cut 1/4in. steel rod and the ceramic blade US540 quickly cuts and shapes Lime Stone tiles, however light or low pressure cutting is need to prevent chipping. The ceramic cut width is ~.094in. See attached photos. Overall I believe the saw blades are well constructed and will have a fairly long life. I would prefer the metal and ceramic blades to have the 3.9in. diameter to allow deeper cuts, and a thinner cutting edge for the ceramic blade.

NOTE: Dremel has provided me this product in exchange for an honest review. I already own the corded Dremel Saw-Max (SM20), as well as the Dremel 20V Max Ultra-Saw Cordless Compact Saw (US20V). The corded version actually uses a smaller (3-inch) blade (SM series), while the Ultra-Saw takes a slightly larger (3.5-inch) blade (US series), so the Dremel Ulktra-Saw Cutting Kit (US700) works only on the cordless version since the blades are 3.5 inches (or 4 inches) in diameter. I think that it would make more sense if both saws accepted the same-sized saw blades for the sake of conistency and interchangeability. This kit includes two 4-inch wood and plastic carbide wheels (US500), three 3.5-inch metal cut-off wheels (US 510), and one 3.5-inch diamond tile wheel (US540); these are the same three blades that are included with the Dremel 20V Max Cordless Compact Saw Kit (US20V-01). I tried out the US500 with 3/4-inch pine board as well as oak flooring, plywood sheets, and 2x4 Douglas fir before moving on to square metal stock and masonry (using the diamond blade; Dremel also carries abrasive masonry blades for this tool, but these are not included with the kit). Here is where the 3/4-inch depth-of-cut limitation really becomes obvious: the saw itself is powerful enough to handle a range of materials, but the depth of cut means that I will be using it only for sheet goods, planking, and 1x stock, for the most part. That still gives me plenty of opportunities to break out this tool and not have to worry about having an electrical receptacle nearby. However, an extra 1/4 inch (1-inch) depth of cut would really be appreciated; this saw didn’t quite cut through the square steel stock that I tested it on. Anyone who wants to invest in the full line of blades and accessories for this tool should keep in mind that several other blades are available for purchase beyond the three that come with the kit: the wood and plastic carbide wheel (US500), the metal cut-off wheel (US 510), and the diamond tile wheel (US540); there are also the abrasive masonry blade (US520), the metal-cutting wheel (US550), the wood and plastic flush cut carbide wheel (US600), and the diamond surface prep abrasive wheel (US410).

This 6 piece cutting kit is one that I like to have on hand because it’s useful for so many different materials. I’ve used the diamond cutting wheel on several tile projects; it easily cuts through floor tile and is faster than a traditional tile saw. The wheel lasts quite a bit longer than I expected it to. I replaced the entire tile floor in my master bathroom and didn’t have to replace the wheel. I also cut cement backer board with this wheel; the cuts are clean and fast! I use the carbide cutting wheel a lot with small wood working projects. The convenience of a hand held cordless tool is a huge time saver, and it’s safer than using a miter saw or table saw because I work with smaller pieces of wood. I’m starting to use the metal cutting wheels more since I’ve realized they are good for cutting more than just pipe. I installed a corrugated metal backsplash in my kitchen using this wheel and my cordless Dremel Ultra-Saw. It really made the whole project move along and eliminated all manual cuts. I have arthritis in both hands so that’s important to me. This is a reasonably priced kit and is compatible with my Dremel Ultra saw and Saw Max. It’s a good one to keep on hand!