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Blades Snap


edward

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 I use a lot of FD #1 and FD #2/0 lately they seem to snap off about 1 1/2 from the top and  thats after I release the blade, I just touch  in and it snaps, never had that problem before. I hav some olson blade, tried them and  no problem. Has anyone ever had that problem. I'am just wondering  if its the quality of the blades.  edward

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If your breaking on release ,sounds like the harden process ,was over done on that batch .try a new one try bending at same point if it snaps you have your answer ,overheating takes hardness out so ,Imho you got some  super hardened blades ,no flex left   in them . especially small thin blade have little room for error .some times the reverse is true they were not hardened enough and bend and dull easily. an easy test (same size same # blade ) place between entended hand between thumb and middle finger and start to flex blade gently making a arc and feel spring action as you gently close and open your hands grip .differing sizes will have differing tention because of difference of tpi & thickness of different sizes ,if it springs back and forth fine , super hard will snap in the middle, soft ones will bow and not return to straight . At least from you limited discription is my assumption ! Hope that helps identify your mystery !

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I agree with Kevin, contact mike and see what he has to say.

Carl is probably correct that something in the heat treat process was probably missed. The steel would have been hardened then tempered back to the correct hardness for the blade. The tempering improves the grain structure of the steel so that it is not so brittle. If they didn’t get drawn back (tempered) then they would be terribly brittle and break wherever the blade would get kinked.

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I did contact Mike a few months ago when I purchased the blades, he gave me some more blades, and with my latest purchase I still have the problem, after the blade is released  and ready to insert it in another hole it snaps about 1 1/2" from the top, and I am careful on threading through the hole. Like I said before I tried Olson blades that I had and no problem.  edward

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It's coming back to me now about blade problems i've had .If it breaks close to the top the blade was to tight on thin ones and if it breaks close to the bottom the blade was to loose or loosen up before changing if that helps you.Thin blades are temperamental You can't tighten the thumb screws very tight either or it severs the blade.These may or may not be related to your problem but i thru it out there for you to decide :cool:

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Hmmm....yah, you should be fine with that thickness.  I'd try to bend them with your fingers and see what happens.

 

Is it breaking where you're putting your clamping pressure (or immediately below)?  I've had that where the clamping bolt had a bur on it and more-or-less cut into the blade.  It would snap my thin blades (mostly spirals) after a few times of clamping/unclamping.  

 

It could also do that if your set screw is slightly below the clamping plane, and the clamping screw is pushing the blade into the recess.  That creates a sheering pressure that will certainly weaken the metal at the clamping point.  Just a thought.  

 

It's just strange that it would do it to one brand but not to another, assuming all other things are equal.

 

 

clamp.png

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The Key to me is where the break is occuring ,basicly in this case it is near the middle .clamp issues breaks will be at the or near the the clamp ,all info is correct about clamps but this is not failure at eitheer clamp area s .,I would save failed blades andd see if failures are all at or near same spot ,then take a pair of pliers and see how brittle the rest of the blade is near the break wit a slight twist of the pliers ,then do same test on olson , that should confurm or dispell quess's !

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  • 2 weeks later...

Thanks so much for all the info. I am a beginner. My blades (nearly all Olson) always break in the same place, near the top. I've been using a Jet saw with different thicknesses of wood. I was told that after I've clamped the blade and am adjusting the tension, I should be able to make the blade 'ping' by 'strumming' it. I always do this, and they still break.

 

I was cutting thinner composite board, but recently started cutting pine, 2cm thick, with 10tpi blades. I go really slowly, cutting at about 1mm every couple of seconds (!), but the blades still break.

 

Thanks in advance for all the marvellous tips!

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I have to say that fairly recently I decided to try FD blades after always using the Niqua brand for over 30 years and I have had a lot of breakages too. I am not the only one, in another Scrollsaw forum I am a member of (UK) quite a few there have reported breakages recently with FD blades.

 

Understandably we all have blades break from time to time but some of the FD blades seems to break one after the other whilst the Niqua blades only need changing when blunt.

 

I assume there must have been a bad batch.

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