CMT543.158.51 Mortise Chisel & Bit Set, 5/8-Inch Diameter, 3/4-Inch Shank

I bought various sizes of CMT Mortise Chisel bits for my Mortising machine. The bits are accurately machined and pretty rough on the outside. I spend about 30 minutes per chisel to polish the chisel but some machine marks were so deep that I could not remove them. After polishing I also sharpened the chisel. The Auger had also many machine marks and I spend 15 minutes per auger to remove the marks and also trim the cutting edges which protruded slightly above the edges of the chisel and caused light drill marks inside the mortise.After this initial tuning the bits are performing good. The bits are holding sharp edges well and eject chips good without any overheating. I wish CMT could decide if they are building long shaft or short shaft Augers though. The 1/4" Mortise chisel and a few sizes up, they are long shaft, but larger sizes like 3/4" and 1" are short shafts. This is not really convenient if one needs to change sizes often, as it requires me to remove the chuck from the Mortiser to put a spacer in for short shaft chisels, and remove it for short shafts.Would I buy them again? I would take a look at Powermatic chisels and Lee Valley before making the decision.Pictures below show chisel how before and after polishing.

Shank was 1/16 larger than the delta mortising attachment.Since in needed 5/8" and only CMT (not Delta) had one, I drilled out the cast iron attachment to accept this one.Would have been 5 stars had it been compatible with the delta out of the box.

These chisels are reasonably good and fairly sharp as received. I was slightly disappointed with the overall finish as the chisel needed substantial honing to remove the grinding marks from the business end. Once the chisel was honed, slight touchup with a diamond cone on the inside of the chisel and some slight sharpening of the auger, it was ready for use. Once 'tuned up' the chisel works very well, I cut over 100 mortises in hard maple and it is still going strong.

I haven’t used it yet, but upon inspection, it looks to be very sharp, well made and worth the cost.

Eh, another you get what you pay for. Morticing bits can easily go $150, this was what, $20. So yeah I cheaped out on it. The steel is really soft . Dulls easily, but sharpens easily as well so that's a plus. I have a Powermatic Morticer and it does not fit the bushings as snggly as the Jet and Poermatic bits, go figure they are the same manufacturer..... I did not feel the CMT cleared chips as well either. I hear Lee Valley has some nice bit inexpensively I will try prior to sinking the big buck.

Nice, but, as with any mortise chisel (and most woodworking tools) you have to sharpen it before use.

Good tool. Used several times with good results.

I am a hobby woodworker but I build fine furniture. I have a really nice cabinet mortising Jet machine. I bought a 4 piece grizzly chisel set and have been using them. I decided to buy one much nicer chisel to build my new bench craft workbench. This thing will not hardly cut. I have tried many different auger positions and sharpening it. I had to use a dead blow hammer to get the chisel out of the wood (soft maple). I took it out and decided to try my old rusted "grizzly" chisel set. 4 chisels for the price of this one. And it's not the high quality Japanese set from grizzly. The cheap grizzly chisel cut thru the soft maple like a hot knife thru butter compared to this piece of junk. I hate it so bad that this is the first review I have ever done. Save your money and get something else.