How straightening blades! A very easy method and A SHORT VIDEO by Eduardo Berardo JS!

THanks for sharing. Watching your video was very informative.
 
Eduardo Berardo said:
Thank you my brothers. I forgot to important information. I recommend you to make a hardening of your straightening hammer, and make a aneeling for fifteen minutes. Example: If you aneeling O1 steel for 1 hour at 480°F, make only the same temperature for 15 minutes!
Proceed the straightening blade with is hardening an aneeling! Regards!
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So the blade should be still be hot when you attempt this after the anneal/temper? Or it has cooled down totally?
 
Well now, the knives are "mucho" !!! and the how to do it are great!! This straightening method is new to me but one I will soon try. Thank you and please come back often to add to our conversations, Your English is very good as Salem said.
Frank
 
Eduardo Berardo said:
Dick, I really do not how to say. The hardening on oil in Brazil we called "têmpera". The heat treatment after, to reduce excessive hardeness, at one or 2 hours in the oven we called "revenimento". That is called "aneeling"? Do I correct? Please, teach me! Thanks!
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têmpera = hardening
revenimento = tempering

annealing is when you heat the blade to critical (or just below critical) temperature like 800C and let it cool very slowly so that it is very soft and easy to grind, drill, or machine
 
Wulf said:
têmpera = hardening
revenimento = tempering

annealing is when you heat the blade to critical (or just below critical) temperature like 800C and let it cool very slowly so that it is very soft and easy to grind, drill, or machine
Click to expand...

Thanks a lot Dick.
Aneeling = Recozimento.
Hugs!
 
Quote Originally Posted by Eduardo Berardo "The blade is cold brother! After hardening!"

The peening on the inside of the curve spreads the steel there and forces the blade to bend in the opposite direction and (eventually) flatten out. The reheating (or re-tempering) of the blade helps to deal with the internal stresses caused by the peening.
 
Thanks for posting this Eduardo! No need to apologize for your English you are definitely no beginner. I saw this in your excellent WIP thread and this may be the most controlled method of blade straightening I have come across. I'll be making one of these hammers soon.

And for the record guys his native language is Portuguese not Spanish ;)

-Clint
 
Obrigado Eduardo! For sure I will learn this method. Thanks again for you're willingness to share your knowledge.
Is the pointed end of your hammer rounded or basically flat?
Where are you living in Brazil?
 
Eduardo,

I think we are all talking about the same thing. The names of the procedures are a little different here but we understand you fine. Here, the hardening in the oil, water, salt or air we call "quenching". The heat cycles afterwards to reduce stress and add toughness we call "tempering". The technique you describe is very interesting. Another member here once mentioned a similar technique someone taught him which involved sandblasting the warp to remove the bend. Same idea. Thanks for sharing.
 
Excellent tutorial :thumbup:
Your English was very easy for me too understand and you should be proud that you are learning another language.

I would definitely watch more tutorials you make .

Again very nice job

Paul.
 
It would seem to be the same as a phenomenon observed in older machine tools. The table surface on a mill will often be slightly high in the center/low on the ends, by several thousandths of an inch after 50+ years in service. Not because of the steel of the table sagging at the ends, but because the sheer amount of work done on the surface and all the little taps and dings and marks it acquires over time begin to effectively peen or stretch the top surface out longer, causing the table to camber along its length...
As it turns out, I've got a blade with a little warp today, so I'm off to try it right now! Just gotta mod a hammer to work.
 
You speaking English is SOOOO much better than me trying to speak to my Wife's family in Argentina! Such great information here!!!! I will use it wisely. God bless and one day I will own one of your pieces!! Jim
 
Parabens e obrigado Eduardo, nao conhecia esa tecnica mais vou tentar aprenderla, poderia descrever o martelo?. Agora sou eu quem pide perdao pelo meu "portunhol" :D

Guys, in Brazil they speak portuguese and down here in Argentina Spanish.


Pablo
 
Eduardo,

I'm curious. The hammering stretches the surface of the blade which causes the correction. What happens when you grind through that surface layer on your way to dialing in the final grind and finish on the blade? If you sand through the hammered layer will the blade want to return to its warped state?
 
Success, or at least a good start.
Have a forged 1084 kitchen knife, 8-9" blade, cold and annealed, soft state prior to HT.
Blade wavey, (couple of small curves) not bad, but couldn't get a good centerline mark. Got out my small ball peen, pulled a chair up to my anvil and went to tapping. Tried to mimic the video here. Very pleased with the results. Will HT and temper soon, we shall see.
Big thanks from South Louisiana.


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wdtorque said:
Success, or at least a good start.
Have a forged 1084 kitchen knife, 8-9" blade, cold and annealed, soft state prior to HT.
Blade wavey, (couple of small curves) not bad, but couldn't get a good centerline mark. Got out my small ball peen, pulled a chair up to my anvil and went to tapping. Tried to mimic the video here. Very pleased with the results. Will HT and temper soon, we shall see.
Big thanks from South Louisiana. Dozier


Sent from my iPhone using Tapatalk
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Bob, but you straightened it before hardening, what Eduardo is showing is after quench and with only a 15min tempering cycle. I have yet to test the method myself.


Pablo
 
Eduardo,

as a bladesmith student using laminated steel blades, straightening blades is a requirement on every blade and is done at least twice in the process.
So I'm very interested. Traditional Japanese bladesmithing uses a brass hammer on a wooden stump after quenching, it's ok to straighten on the anvil in the annealed condition. I do struggle with getting a blade perfectly straight and it's hugely important to be straight in order to have the core centered when bevel grinding.

This method looks to be a very useful tool for me.
Would you be kind enough to show a closeup detail of the hammer you are using and indicate the weight of the hammer? Edited - Oh I see it now in post #54 of your other thread! :-)

2114A1BA-8F95-42D2-95B1-5B4A52C35A0A_zpsfvxjxoac.jpg


regards
Harbeer
 
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HSC, would it be correct to say that straightening a laminated blade is done from the convex side, and is a very different operation due to the inherent flexibility of a blade made with a martensitic core and cladding that remains soft? A wooden surface would have just the right give for that. I routinely straighten mono blades of common alloys before they cool enough to become stiff, using the same "stump" technique but on my anvil (which has a remarkably flat face for a tool used since 1895).
I've seen Carter, somewhere in his youtube channel, demonstrate a technique very similar to Claudio's, using a cross pein hammer to spread soft cladding from the concave side.
 
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