Accidental Test Of Shopsmith Combo Blade Versus A Brad

[algale]

I was helping my wife with a project which required me to rip and cross cut some 3/4 thick plywood shelves down.

Unknown to me, there was a 1.5 inch brad embedded straight into the edge of the plywood and right in line with the rip.

I was using the Shopsmith think kerf combo blade. I didn't notice anything unusual during the cut. Afterwards I saw the brad, or rather half of it. It had been ripped almost perfectly down its length, just slightly off center, leaving behind a smooth and almost polished surface.

I inspected the blade and saw no obvious damage and made a one more rip and several cross cuts with no obvious adverse consequences.

Any reason I shouldn't continue using it?

[BuckeyeDennis]

I've continued using the Freud blade that sliced a #10 screw lengthwise, described in this thread. No problems encountered to date.

[dusty]

The only precaution that I take when I do that is to inspect the carbide. Now you said a brad and what I see when I thing "brad" is not going to dislodge the carbide. I've ripped screws, as you described, and I have cut nails. Now none of this is smart and is certainly not good for your saw blades but is not reason to discard the blades.

If you do find loose carbide, be aware that it can be fixed. I send blades to Forrest when I need that sort of service.

[algale]

Cleaned the blade thoroughly and see no damage and felt no loose carbide.

I will continue to wear a full face shield, which has become my practice in the last year or so anyway.

[Ed in Tampa]

Cleaned the blade thoroughly and see no damage and felt no loose carbide.

I will continue to wear a full face shield, which has become my practice in the last year or so anyway.

Unless the full face shield is ballistic glass all you are doing is providing plastic shrapnel should a carbide tip comes off and hits it. I have many carbide blades that have cut through many nails, bolts, and other pieces of metal. Never had a problem. Of course I NEVER! NEVER stand in line with a rotating saw blade.

[algale]

Safety glasses?

[reible]

I too have cut a few things that, well were not intended to be cut with a saw blade. So far nothing bad has happened to me or the blades involved. I don't like it when it happens and try to be more careful but then that is about all that happens.

I have in my youth had some knots come loose and zing around, learned my lesson well and look out for loose knots.

I had two shopsmith blades from back in the 1980's that lost teeth, never noticed them flying about or hitting anything and while cutting I never hit anything that I know of so it was a mystery. Those are the only two blades I ever trash canned. Those were also the last blades I got from shopsmith. I had never before lost a tooth or after, just on those two blades. Just enough to turn me off the shopsmith blades.

I do keep the bottom guard on and use the top guard for through cuts. And yes I do keep away from nails and the like as best I can. I have no desire to get hit with any flying objects.

Many many years ago a friend got some walnut which I helped him cut up for part of the wood. It actually had some embedded gravel that did not show up until we started cutting it, it was on an 18" band saw so all it managed to do is wreck the blade. Cut that area clear and life went on. That was before I had a metal detector and even then the rocks would not have shown up.

Which reminds me I think I better check the battery in the detector, I hope it has not leaked and messed things up..... kind of for got about it since I haven't used it this past year. Well something I can do in the cold garage today. It was down to 35 degrees when I turned the heater on. Waiting now for about 45 before I got out and do some things.

Ed

[Ed in Tampa]

I have also lost carbide tips from saw blades. I don't know when or where they went but it wasn't from hitting nails because those blades never hit anything to the best of my knowledge.

Never lost a tooth from a Shopsmith blade. Don't remember the names so I won't guess.

Had some trees trimmed in my yard. The Arborist told some interesting stories of things he has hit in trees. One was poured full of concrete that the tree completely grew around, plus pipes, nails, chains, a small motor head casting, even a lawn mower muffler completely grown into the tree. He said chain and screw eyes are most common only surpassed by nails randomly driven in and grown over.

[jsburger]

My guess is that a carbide tooth weld that has been compromised to the point of failing will do so at the point of highest stress. That is probably where the tooth enters uncut wood. Since the tooth is going down at that point it does not get flung at the operator. Even coming up through the kerf on the back side probably puts more stress on the tooth than just the centrifugal force of spinning freely.

[dusty]

That may be valid theory but I don't want to be in the shop when it gets proven - one way or the other.