Broken Tooth

nn4jw

Jim
Senior User
No, not mine.

This morning I was out in the shop working on a project and ripping the edges on some 2x4's. Poor man's jointing. There was a bang, something stung my chin followed by the fairly loud loud and sharp sound of something metallic hitting either the garage door or one of my rollabout tool boxes. I immediately stopped the table saw and checked my chin. Thankfully there was no blood. Next I checked all the teeth on the tablesaw blade.

Here's what I spotted.

186976


The tip of one of the carbide saw blade teeth was missing! You can see where by looking at the picture where I marked the tooth location.

The only thing I could guess that caused this was hitting a hard knot in the 2x4. Nothing else seemed odd with the wood at all. The blade is a Freud 30-tooth glue line rip and I've always been happy with it. That said, I did just notice that the blade is marked for ripping woods up to 1" thick and a 2x4 is thicker than that, but my money is on hitting a vary hard knot that the carbide just wasn't up to.

Now for the cautionary part of this tale.

I'm embarrassed to admit that I wasn't wearing safety glasses when this happened. I don't think an eye would have shaken this off as well as my chin did. That's on me and I got lucky. But I do learn from mistakes I survive. I installed an old non carbide tipped rip blade, put on my full face shield and finished the remaining cuts. You better believe I'll wear safety glasses at all times in the shop now and the full face shield any time I'm doing anything that can generate high speed shrapnel, e.g. grinding, working on the lathe, using the table saw.
 

MarkE

Mark
Corporate Member
Glad to hear that none of your personal parts got too damaged.

I have had a couple of close calls with flying debris and like you I have learned to always wear my safety glasses in the shop.
 

bob vaughan

Bob Vaughan
Senior User
Years back I had a blade that had a tooth failure. I was wearing a full face mask at the time. Being sort of bent over and my head somewhat down, the shield was about at a 45º angle. The carbide hit the shield and deflected downward at my upper chest. I pulled down my shirt and undershirt to see a tiny spot of blood. I felt like I'd just aced a pop quiz in a safety class.
 

kelLOGg

Bob
Senior User
Many teeth had to hit that knot but only one didn't survive. I think it was a defective tooth or blade. Glad it didn't hit you!
What kind of wood? When I think of 2 x 4 I think pine - but it must have been a much harder species.
 

Jeff

Jeff
Corporate Member
Many teeth had to hit that knot but only one didn't survive. I think it was a defective tooth or blade. Glad it didn't hit you!
What kind of wood? When I think of 2 x 4 I think pine - but it must have been a much harder species.
A pine knot or very hard wood wouldn't have broken the tooth. I too think that it was a defective tooth and not the wood!
 

nn4jw

Jim
Senior User
Many teeth had to hit that knot but only one didn't survive. I think it was a defective tooth or blade. Glad it didn't hit you!
What kind of wood? When I think of 2 x 4 I think pine - but it must have been a much harder species.
Hard to say, but if that was a defective tooth it had lasted through 7 years of a lot of use. I can tell from my Amazon order history when I bought it. The 2x4 was just a BORG 2x4 and one of the usual ones found there in the pile. It may have been sitting in the shop for a couple or three years though. I ususally keep some on hand. Over time those knots, especially if very resinous, can get pretty hard.
 

sawman101

Bruce Swanson
Corporate Member
Many years ago I was sawing logs on my old saw mill; when the blade hit a knot, which wasn't unusual, the knot ripped loose and ricocheted off the board table and into my two front teeth. That smarted! I was thankful that even though it felt like they were gone, I still had the two teeth securely in my gum. I did end up with a very fat upper lip though. After that, I always wore my helmet with face shield when top sawing. I never stand in line with the circular blade of my table saw as that is a danger zone. I do stand directly in line with the band saw and scroll saw blades though.
 

nn4jw

Jim
Senior User
I never stand in line with the circular blade of my table saw as that is a danger zone.
Actually, I don't either and wasn't when this happened. Unfortunately the flying chunk from the tooth went wide to the left where I was standing and hit me on the left side of my chin. If I had been in line with the blade it would have missed me completely. Still not standing in line though.

All bets are off when chunks of blades are flying.
 

TENdriver

TENdriver
User
I always try to wear my safety glasses (and hearing protection) but there’s always those tiny little tasks that take “half-a-sec” to do.

My general solution has been to have two dozen pairs (yes, literally) laying out all over the shop. Pretty much try to have a pair laying within arms reach no matter where I am working.

Even that extreme isn’t perfect when the job will take just a second...
 

Dean

New User
Dean
Wow... I’d say you got lucky...glad you weren’t hurt. I had a piece of wood get in my eye 10 years ago doing a rip cut that “would only take a second”. It eventually got better but I’m a believer now that anytime a tool turns on the saftey glasses are on my gourd.
 

Roy G

Roy
Senior User
Jim, in your picture of the blade, there is a shiny streak in the body and some sort of smudge on the blade just ahead of the broken tooth. Could there have been some nail or bullet in the 2x4 that you cut through?

Roy G
 

nn4jw

Jim
Senior User
Jim, in your picture of the blade, there is a shiny streak in the body and some sort of smudge on the blade just ahead of the broken tooth. Could there have been some nail or bullet in the 2x4 that you cut through?

Roy G
I didn't really see anything but there certainly could have been. For sure something chipped that tooth.
 

Tarhead

Mark
Corporate Member
That blade came into contact with something harder than Pine. Check out the abrasions/shiny spots at the base of each tooth and the big gash by the expansion cut
Untitled.jpg
:
187062
 

Our Sponsors

LATEST FOR SALE LISTINGS

Top