Wolfride 4pcs Long Shank Tungsten Carbide Burr Set 6mm Shank Die Grinder Burr Set for Metal 6-Inch Length

these are listed as use in die grinder,these will wobble and bend when grinder is turned on, I cut length down to 4 on a new one and it still was so out of balance it almost hurt me, needed to complete a task so ran in a 3000 rpm drill and was able to use it. I would caution you to not spin these very fast. you might get hit in the face.

Very well-made and strong stay sharp for a long time I used mine on cast-iron and they Are still sharp

Broke with in 5 minutes of use. Was using to bore a nut bigger for a bearing driver ended up using a socket.

using for boat fiberglass repair, and very satisfied so far.

Manufactured to high standard the shank is strong and grinding tips seem to work on most materials.

They tend to wear down too quickly for being cobalt.

I’ve only used on porting mostly aluminum some steel 2strokes for a couple hours but they don’t seem to be wearing at all yet. They can be cut a little shorter or you can hold the shaft with your callus or greased fingers. It will kinda bite and chatter or skip if you don’t hold it well a little closer to the burr. Good value same as eBay

works great in a drill. when used in an electric die grinder, the lack in thickness allows flex and a lot of wobble in the bit. to cut down on wobble, a couple of inches will need to removed if prefer to use in die grinder.

Did.job

The Steel used for the Shafts is Waay too soft. As soon as I turned on the Die Grinder, the Shaft bent 45 degrees just above the Collette. Just to make sure the one Cutter was not defective I tried a second one and the Same thing Happened. I then Cut off the 5.5” Shaft down to 2.25” and tried it again and at least the Shaft did not immediately Bend. Now to see if the Shaft is Strong enough to do the Light work on some Aluminum Without Bending so bad it becomes Useless.