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I got a new blade for Christmas (Hibben  IV).  Made of 1090. Was going to sharpen it but the middle of the blade is to hard.  I think it has a bad heat treat.  Can I reheat treat a blade or will this just make it worse. If I can. What should i do.   Thanks

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Was using a flat file to start off cause there wasn’t much of an edge to start with.  The file would bite in fine on the tip and back of the blade. But the middle of the blade was very hard and brittle feeling. The file would glide over it like ice. Just saw some reviews on this blade and a few brake in the middle. That’s what worries me.  Not sure what you mean by sticky.

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Merry (almost), Camo

Where are you? Put your location in your Avatar. Some parts of the world, it is already Christmas Day, other parts knot.

To re-Heat Treat the blade, you need to know what material it REALLY IS. If someone says it is 1090 and didn't Heat Treat correctly, What else shouldn't be believed? To re-Heat Treat, the handle will need to be removed. Will this relegate the Blade to be a 'Wall Hanger'?

A simple question will not have a simple answer.

Merry Christmas!!


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Well if you don't want to spring for testing then you could do a slowly ascending temperature heat treat. The lower ones can be done in a kitchen oven IF you get a oven thermometer to be sure the temperature is what you think it is.  Start at say 325 degF, bake the blade for an hour, let cool and test the hardness.  if still too hard go to 350 degF continue stair stepping until you get the hardness you want.  

Note that if the tip is already "soft" then any more tempering will not be a problem.

Some knives; particularly of the high tech alloys basically require diamond hones to sharpen.  I avoid those for the most part.

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On 12/24/2018 at 3:55 PM, Camoman said:

 The file would bite in fine on the tip and back of the blade. But the middle of the blade was very hard and brittle feeling.

I spent a few minutes reading reviews of this blade and my opinion is that it's quickly produced without a lot of quality control.  Several of the issues people complained about could definitely be the result of poor heat treating.  At first I thought perhaps there was an intentional differential tempering done  on it to make it less likely that the tip area would break off, but after reading a bit I think it's just shoddy workmanship.  Since it is a machete type of blade you probably don't want it quite as hard as the middle part appears to be, but in general you don't really want to be able to sharpen a good knife with a file. If you can then it's softer than most of us want for edge retention. Usually a harder blade will hold an edge better, but it will be more prone to breaking (rather than bending) with heavy use/abuse. 

If it truly is 1090 steel you could do the entire heat treatment process yourself (after researching the specifications) and achieve a better result, but if this is something you've never done before I'm not sure I would recommend it.  As long as you don't mind too much about the soft tip, as Thomas indicates, you can try tempering the entire blade at progressively higher temperatures until you get the result you want. You won't make the currently soft spots any softer unless you raise the temperature high enough to soften the entire blade past that point.  However, you can soften up the really hard spots a bit by tempering at the right temperature.  If it is 1090 my guess is you'll end up between 400 and 500 degrees F before you  get the desired result.

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