Can Carbide Saw Blade Chips Kill?
There's no source for the rumor that a carbide saw blade fragment struck a woodworker in the heart. But woodworking kickback is deadly dangerous — no doubt about that.November 14, 2014
Question (WOODWEB Member) :
I recently heard a story of a solitary woodworker sawing some 8/4 maple in his shop. When he did not come in for lunch, his wife found him dead on the floor, the tablesaw still running, but no apparent reason for his death. The coroner found a carbide tip had apparently come off the saw and pierced his heart, killing him instantly. No info on what he might have hit.
This has the sound of an urban legend, but I have not done the math - saw rpm, tip speed, and mass of the tip. Plus the likelihood that the energy in the tip may have been dissipated by whatever caused it to break off. Also the geometry seems to say that the tip would end up in the base of the saw - maybe.
I once found a tip in my shirt pocket after a day in the shop that included hitting some hardware in a board on the table saw. That broke off several tips, but I did not feel any tips hit me. Although I think I may have heard the same story about the guy with the tip in his heart at lunch the next day when I mentioned I found a tip in my pocket.
I have hit lots of bullets and shot - lead and copper jacket types - and like to feature them in the finished products if I can. They hardly phase HSS knives, much less carbide. I have hit my share of other junk also, but maybe I should test my reaction time to see if I can dodge a lethal tip?
Forum Responses
(Architectural Woodworking Forum)
From Contributor M:
Sounds hard to believe but maybe the guy was working bare chested and was thin skinned. I had a buddy who owned a vintage sawmill that he'd converted from water over to diesel power. His primary business was wide pine flooring. I was there one afternoon when a tree someone had given him went on the mill. The metal detector somehow missed an electric company anchor buried deep in the log. The anchor and blade insert shot through an oak wall about 35' back from the blade. Left a hole like you'd punched it with a 12ga slug. It would have been a fatal event for someone back there. I could see a tip coming off a large circle mill killing someone but I can seem to get my head around it with a 10"-12" saw and the mass of a tooth or tooth fragment.
From contributor J:
About two years ago I was resawing old oak beams from a log cabin (keeping the hand hewn sides for a coffered ceiling project). They were very heavy and took most of my strength to get them pushed through the saw. I tried to de-nail them best as I could, but the saw caught a cut nail in the tail end of the beam. The nail exploded and shot all over my face and shirt. I was bleeding over my top lip where I was certain bits of the nail had cut me. Two nights later, while picking the scab off of my face, I saw the shiny surface of a carbide saw tooth! The whole tooth had been embedded in my face for two days. My Delta unisaw isn't powerful enough to impale a saw blade into my heart, but it certainly is powerful enough to put an eye out with an errant piece of carbide.
From contributor S:
I have heard a similar story involving a shaper cutter that was not tightened properly.
From Contributor R:
A friend of mine who is a cabinetmaker never used to wear safety glasses until a carbide tip imbedded itself into his right eyebrow. He now wears safety glasses…
From contributor K:
I just did the math, and a 12" saw does just under 120 mph, so a 10" would be around 100. I think that is too slow for that small a projectile.
Larry
From contributor L:
Too slow to kill you but fast enough to put an eye out!
From Contributor W:
I have been hit by a tip - nothing to laugh at I assure you, now I just feel lucky.
From contributor D:
I don't know about a carbide tip, but I had an employee send a split board straight through his wrist. That same board would have probably penetrated his chest cavity. I also had a board kick back, travel about 20 feet and penetrate four layers of 5/8" drywall and imbed in the metal siding on the outside of the building. Kickback is nothing to laugh about.
From contributor V:
While cutting melamine on a PM-66, I had several carbide tips come off of a brand new blade and hit me in the chest and arms causing painful but minor injuries. There was nothing in the material to cause this to happen. The manufacturer’s rep told me that they just put a new brazing machine into service and were experiencing some failure of their blades. It was replaced without hesitation and the only question was whether the guard was on the saw.
