Wokesi 10Pcs,1/4"Cut Diameter,1/8''(3.175mm) Shank,Tungsten Carbide Cutter Burrs Grinding Head Fit Bits for Rotary Tools (1/4''*1/8''Shank)

I bought these to use on the objects I 3D print. I print mostly from PLA, PETG and TPU. While I usually try to design my objects to have all physical features needed (such as gaps, holes, proper alignment of holes, etc.) I either miscalculate a feature location or for print stability reasons, omit such features in the model and add them after printing. Two examples:I recently designed and 3D printed some guitar speaker cabinets. Despite getting the speakers' bolt circle diameters from the manufacturer, the mounting holes for the speakers were a bit off. I simply used one of these burrs to elongate the mounting holes slightly.On occasion, I'll 3D print hollow forms to make LED powered lamps. With some model geometries, if I try to print them hollow with no solid bottom layers, the print has a very high failure rate. So, I'll print the model with a couple of solid bottom layers to add stability, then drill a small hole into the bottom of the model after it's printed, and widen the hole as necessary with one of these burrs.Okay, onto using the burrs themselves. I've always gotten by with using the smaller, finer burrs that have been included with the rotary tools I have, but I've worn a few of them out, hence my buying these.For PLA and PETG, these burrs chew into them like nothing. I've nearly ruined some prints because these burrs will gladly grab into whatever surface I press them in to and start ripping into it. So for slight machining or touch up work, I'll use one of the more mild burrs in my arsenal. But for instances, like the second example I listed above, these burrs are a real boon and make the job much easier! I've only used the burrs on the aforementioned materials, but should the need arise, I'd feel confident using these in tougher plastics, and in the right situation, on some metals. For my needs, these are great for hogging material out though!

Switching out handlebars on my motorcycle and I needed to remove the old lock cylinder from the steering head. This required drilling out 2 x 6mm bolts. Easy with the first one, not so easy with the second one. I needed to grind away the rest of this stud and was having no luck going back and forth with drill bits. Ordered this set and hoped it would work. They did. And quickly too. Had the bolt out in minutes. Just be aware, when these bit catch, the kick is pretty forceful. Not sure why or what they were catching on, but it was pretty scary when they did. Glove and eye protection and don't mind mucking up whatever you are working on.

I bought these to use for an auto restoration project I'm doing. Specifically I've used them so far to grind off the casting marks on the brake calipers and to grind down some welds . These things worked great. They're just small enough to allow me to get down to the finer details but still get things done fairly quickly. Would recommend to anyone doing similar work.

They look like really nice burrs, I'll update the review if they prove otherwise. I will be using them weekly as an automotive technician

These bits cut two different materials quick. First I was cutting some hard rubber, it cut it like butter with no burn just lots of small shredded pieces. I then cut some steel. I was kind of reaming out a hole that I did not want to cut all the way through. For this cut I used both the side cutting edge and the very helpful bottom cutting edge. If I bought this item sooner I would have saved 4+ hours work!

I needed to trim some cabinets and I tried a file, but the space was too small for a regular size, so I bought these to try. They worked great, saved me a lot of time as I could attach them to my drill instead of trying to file the cabinet by hand.

I don't know what I'm going to do with five of these. I used one to ream out a couple of holes in a set of steel strut brackets and while there was some chipping evident along the sharp edges, it still cut through the metal without any issues and it looks like that original one will last a few more jobs.

I have used few of the pieces for grinding on metal with great success and the bits are still like brand new. I'm impressed.