Weiler 56490 Mounting Mandrel For Cut-Off Wheels W/3/8" Arbor Hole, 1/4" Stem

Wheels work well and the arbor is a good piece to have in case you want to use it on other grinders !!

Bought these items for work. I have cut multiple materials, and these wheels work exactly as designed.

Well made also got them on sale otherwise they will be kind of expensive ,perfect for my Milwaukee m12 die grinder

I have two of these in two different grinders. They were both (and/or my grinders' collets) a bit out of whack..One of my grinders normally runs rather smoothly. But with this mandrel chucked in it, it vibrated so bad that the cutoff discs frayed, the switch fell apart, the power leads broke off, and the case "ultrasonically" welded itself together in two spots. I had to tap it with a hammer to get the halves apart.After repairing the grinder, I chucked this mandrel back in and "turned" it true with a thick cutoff disc in another grinder while this mandrel was spinning at 25K rpm. You can easily see where the high/low spots are, due to the black finish. When there's no more black, it should be better. After making it concentric and removing a bit of unnecessary mass from the head, the vibrations went away. I also noticed the discs did not sit flat, so I took the screw out and faced the part that the bottom of the disc sits on, too, using the same method. Unfortunately, I had no way to face the bottom of the disc retaining screw in situ, but it was close enough to begin with that the discs now sit perfectly flat, and I did not need to fudge with it by, say, adding a cardboard washer or an O-ring between the disc and the retaining screw. The grinder is now super smooth and working fantastic with this mandrel. I think I'm gonna dedicate this grinder to cutoff discs, changing them out only with the mandrel screw. I'm afraid I might lose some smoothness/concentricity if I re-chuck the mandrel.These mandrels are made of carbon steel and the screw and threading are fine. They are solid. They are cheap enough that I would recommend them. Just have another grinder or Dremel tool handy, I think after going through this, I would true up any large mandrel in situ on any tool rotating at ridiculous RPMs, unless it were chrome plated and extremely well balanced to begin with. It's very fast and easy. Just keep both grinders oriented the same direction when you grind: tip to tip, butt to butt. If you try to "69" it, the cutting disc will just loosen, itself. This makes me wonder how reversible air grinders keep the cutting disc in place.

Easy installation durable

Love the big flat head screw, very easy to tighten & loosen up. As well as the variety of being about to go 1/4” to 3/8@ holes.

Works fine but after several times of removing the screw to change disc the screw would work loose during use. Placed Teflon tape on the threads and that solved the problem.

It works. What more could you ask for?