Stanley precision saw set breaks saw tooth

[Bencuri]

My first ever approach setting a saw:

I have a Stanley 15-640 saw set, this one has a rotatable rounded anvil with numbers and a magnifier lense. The instructions on the box says the anvil has to be rotated until the correct TPI number shows up in the lense, then the saw can be set.

I tried to set my old Atkins REX Silver Steel saw with it. The number on the blade is 4-, I measured it, the TPI is between 3 and 4. The minimum TPI on the mentioned Stanley saw set is 4, so I set it there, I thought it won't do harm if I add lesser set than a 4- requires. The problem is even so, already on the first approach, the tooth was broken. 

If I understand it correctly how these saw sets work, the user has to grip the blade and then press the handles until the plunger pushes the teeth onto the anvil. I guess this touching of the anvil guarantees a uniform set all along the blade. Now this was the problem in my case. At halfway it was still okay, but as soon as the teeth touched the anvil it broke off. 

I went on, some teeth survived, but after breaking 2 more teeth I stopped the process. Then I experimented a bit, and noticed if I don't bend the teeth fully to touch the anvil, the process will be successful (it is not possible to maintain a uniform set this way though). I also noticed that on my 8 TPI saw, if I selected 8  on the anvil, it did not break any teeth off. I also noticed that if I set the anvil to 5, and set the 4- saw with it, the teeth survive without breaking.

So what did I do wrong and how should I modify my process? Should I set a higher number than the real TPI and set the saw like that, or maybe it would be better to remove the anvil, and have another one machined  instead that has a lower angle cut in it and use that one? The angle on this one now is about 24°

[enjuneer]

I tried to set my old Atkins REX Silver Steel saw with it. The number on the blade is 4-, I measured it, the TPI is between 3 and 4. The minimum TPI on the mentioned Stanley saw set is 4, so I set it there, I thought it won't do harm if I add lesser set than a 4- requires. The problem is even so, already on the first approach, the tooth was broken. 


So what did I do wrong and how should I modify my process? Should I set a higher number than the real TPI and set the saw like that, or maybe it would be better to remove the anvil, and have another one machined  instead that has a lower angle cut in it and use that one? The angle on this one now is about 24°

I don't think you did anything wrong. The point of bend on the teeth that didn't break seems to be okay. It should be about 1/3 to 1/2 of the height of the tooth from the bottom of the gullet. Your 100 year old Rex may just have brittle steel. There could also be some pitting or small cracks that let loose when the set was applied.

If there is enough height left in the blade, you might consider having it retoothed and use a minimal amount of set when sharpening.

[Pedder]

The numbers on the anvil are just numbers and don't say that you should use the 4 on 4 TPI or 4 PPI.
The amount of set depends on green or dry wood and the maximum of set depends on Blade thickness.
Nothing to do with the pitch.

Cheers
Pedder

[CStan]

My guess is that you set the teeth too low and opposite the direction they were already bent. Doing these two things will break teeth on old saws with hard steel. Never set a tooth in the opposite direction of the set it already has.

It may be that the teeth didn't need to be reset at all. It takes many sharpenings before you lose enough set to make a saw bind. If it wasn't binding in the cut, you should have just left it alone. A lot of saws need less set, not more, which means peening or squeezing out some of the set which is a whole 'nother kettle of fish.

People sometimes acquire a saw set and all of a sudden every saw in their shop needs fresh setting. Try not to be one of those people.

[Timberwolf]

My guess is that you set the teeth too low and opposite the direction they were already bent.  Doing these two things will break teeth on old saws with hard steel.  Never set a tooth in the opposite direction of the set it already has.

It may be that the teeth didn't need to be reset at all.  It takes many sharpenings before you lose enough set to make a saw bind.  If it wasn't binding in the cut, you should have just left it alone.  A lot of saws need less set, not more, which means peening or squeezing out some of the set which is a whole 'nother kettle of fish.

People sometimes acquire a saw set and all of a sudden every saw in their shop needs fresh setting.  Try not to be one of those people.

.............
My guess is that you set the teeth too low and opposite the direction they were already bent.

My thoughts as well....sometime in the life of the saw, some teeth may have been bent the wrong direction.

[bandit571]

Compost happens...

   
From time to time..

[Bencuri]

.............
My guess is that you set the teeth too low and opposite the direction they were already bent.

My thoughts as well....sometime in the life of the saw, some teeth may have been bent the wrong direction.

I set the teeth to the same direction that they had been bent in on the saw. So that cannot be the problem. I think it is the angle on the anvil that is not correct. I have a same age Disston saw as well, 8 TPI, I set the anvil to 8 (that is 8 TPI according to the instructions on the saw set box), none of the teeth broke but the set done is very agressive. It is a lot of set. Maybe it is only useful for raw green log cutting, but way too much for anything else. So I decided that I deassemble this saw set, and have a similar anvil machined, with maybe half as much angle (about 12°). I have set this lower angle to the Atkins REX saw by eyesight, it worked, nothing broke, but by eyesight it is very difficult to keep uniform set, and for particular teeth I had to readjust the set and bend them back a bit with another old fashioned saw set. I know it is prohibited for saws but the teeth did not break in that case either.

[Bencuri]

My guess is that you set the teeth too low and opposite the direction they were already bent.  Doing these two things will break teeth on old saws with hard steel.  Never set a tooth in the opposite direction of the set it already has.

It may be that the teeth didn't need to be reset at all.  It takes many sharpenings before you lose enough set to make a saw bind.  If it wasn't binding in the cut, you should have just left it alone.  A lot of saws need less set, not more, which means peening or squeezing out some of the set which is a whole 'nother kettle of fish.

People sometimes acquire a saw set and all of a sudden every saw in their shop needs fresh setting.  Try not to be one of those people.

The saw in question definately needed to be reset because it was wandering to the right and was getting stuck all the time in the cut. It needed to be sharpened and the set evened out because the set was very irregular. Now the saw works perfectly, even with 3 teeth broken, luckily they are at the portion below the handle so they don't disturb me during cutting. The set is not 100% uniform because of doing it by eyesight but still the saw is not wondering. I ripcut a 14"  black locust log in half that was 25" long, the cut is fairly straight now.

[toolmiser]

My Dad had about 5 Keen Kutter saws sharpened about 45 years ago. When we picked them up, the sharpening person admitted to breaking a couple teeth. He said they were just brittle. He knew saws. I wish I knew someone who could get things as sharp as he could, they were hard on your hands after he got hold of them.

[adamcherubini]

Love the title “saw set breaks tooth”. Like a news story from the onion. You broke the teeth. Pedder is right, the numbers are meaningless. I’ve never used 4 on any saw. I think I set the anvil to hit somewhere around the top third of the tooth. Try again. Be gentle. Slow steady pull.

And saws saw crooked for lots of reasons. And teeth can break sometimes due to too small a file used. Gullets get too sharp.

Glad you are trying and asking. It’s a key skill and not necessarily an easy one to learn.