Dremel 9901 Tungsten Carbide Cutter

Got this to cut/shape acrylic sheets. Did a fast and effective job on 1/8 material. Fit perfectly in my HF rotary tool too!

I have gotten around 10 of these bits. They ship very fast. Cheaper then what I get them for at my local hardware stores. I love these bits. They can break pretty easy if you are careless and don't know how to properly use them. These are made to run at higher speeds When used on metal. I use them almost daily to cut away at stainless steel. They work excellent 👍. Their really great for softer metals like brass, aluminum, plastics too @lower speeds. Just an all around great bit. Wide variety of uses. When in doubt, get the tungsten out. Last awhile for me and I'm fairly hard on bits. Just remember high speeds light ish pressure. Don't be in hurry and they won't let you down. Will be ordering from here anytime I need new ones. Very recommend.

I needed to remove about 1/8-3/16 inch of steel from a 1 inch slot so a disk grinder would not work. The steel was about 3/16 inch thick. There were four slots to do in total. I also had never used a Dremel to remove steel. If you keep the speed no higher than medium and be patient, you will get the job done. If you try going to fast, the Dremel may overheat and you may get bouncing on the bit. The bits did the job. I bought two expecting to either break one or wear one out, but I never used the second bit. Did it with one bit. The job took just about 15-20 minutes. I would definitely recommend the bits.

Works. Cuts quickly. Doesn't overheat.

I bought this cutter to make a square hole in a metal stud - the type of metal studs used to hold up drywall in high-rise apartments/offices. The cutter worked great, it moved through the metal stud no problem. I did however have 2 problems that I'm writing this review so that others can benefit from my experience: 1.) The cutter is relatively short. I was trying to cut metal that was behind some drywall. So the cutter had to be long enough to get through the drywall and through the metal. Because of an obstruction on the wall surface, I had to hold the tool about 1.25" away from the metal. This made it so that only the very tip of the cutter would contact the metal. While it worked I can comment that the tool is very short, so consider you application before buying. 2.) The cutter is very brittle. I actually cracked the shaft of this tool and could not complete my job. Because of my particular use, the cutter was bouncing around a bit in the slot I was cutting. This caused the bit to break. After it broke, i used the remaining portion to try to cut again. It broke a second time. Final recommendations: This cutter is good for controlled cuts in mild metals where you can brace/secure the work and the tool. This tool is not very good for free-hand cutting as I was doing. Make sure that you control the tool well to prevent bouncing and cracking of the bit. I think I will re-try with a thicker-shanked bit. Perhaps 3/8" if I can find one.

I was adding some new gear to the outside of my Jeep and ended up with two pieces of heavy gauge steel pieces from two different accessories that overlapped each other and didn't mate up properly on one side. Nothing huge, but enough that a couple of bolts weren't quite lining up where they needed to go. A few rounds of loosening and tightening the other bolts involved and trying some "percussive persuasion" didn't change the situation, so I decided to try extending the recalcitrant bolt slots a little bit. Tried a set of metal files I had without much luck - they were too fine and only removed an infinitesimal amount of metal each stroke - so I decided to see if Dremel had something that could speed things up. Not something I'd use to remove serious amounts of metal, at least not from the heavy-gauge stuff I was dealing with, but for extending the slots the extra 1/4 inch or so that they needed, the 9904 cutter got things done quickly and with good control. Hindsight being 20/20, if I had to do this over again I'd wear some light work gloves or even just latex ones since the metal comes off in a spray of small particles that took repeated washings to get off my hands afterwards. Ah well, live and learn.

I had to slot some holes in 16 Ga steel, because my holes weren't perfectly aligned. This cut through the steel like butter - I've used other Dremel bits that weren't Tungsten Carbide, and they had a tough time with steel like this. I thought I might need a lubricant, but these just blasted through without slowing down. You definitely want to wear safety gear - dust mask, eye protection, thick gloves - when you use this. It will shoot out tiny bits of steel into you (I got some in my fingers because I didn't have gloves at first). Just a reminder - not a negative of the bit! It does show the contrast between the other bits I used and these - I didn't need the gloves with the bits that didn't work well, because they didn't remove large enough bits of steel to cause a problem. It'd be nice if it were a little less expensive, but it does work great.

I work in a machine shop and I've been borrowing a co-workers ancient Ryobi with this bit on several projects for small intricate work. I finally decided to pick up my own rotary tool (Dremel) and two of these bits. I love these bits ..to bits. Small, strong, and sharp. They also put up with reasonable punishment. For example, I needed to slot a couple holes in some fairly thick steel sheet metal covers today. The holes were clearance M5 diameter (about .219"). I knew it was way to small for even my tiniest die grinder bit, so I brought out the Dremel with the tungsten carbide bit. Well.. The tool apparently didn't like my grip at one point and violently chattered around in the hole for a split second before I regained control. I wager that would have broken (or at least chipped) any other bit of this size on the market, but this bit still looked like it had just been taken out of the package. I've abused these so many times but they keep cutting like nothing ever happened. I will definitely buy more if I ever manage to break one.

Lo utilizo con un moto tool milwaukee de 12 volts y funciona de maravilla. Desbasta el material con mucha facilidad y es muy resistente. Se atoro en algunas ocasiones por descuido mío y reboto fuerte pero no se dobló ni se rompió.

Good bit for metal cuts. High speed rotary tools tend to jump and these will break easily. Might want to get 2 if doing free hand work so you're not stopped part way through a task.

Very good product & also packed & couriered very well very good seller

さすがというか、とても良いです。 ドルメルの4000と4300で使っていますが、かなり固い金属を削っていてもあまり摩耗することなく長く使えます。 他の商品で安いものもありますが、仕事で使うので他の商品は使おうとは思わないです。 固い金属を削るならこれ一択です。

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