So can you sharpen away the tempered area of a knife?

Over time can a knife's temper be sharpened away? I have a couple knives that are noticeably different in their edge holding ability as they have been used. Is the temper throughout the blade or just along the edge.

I was wondering the same thing last night. I was doing a polish job on one of my AR triggers when my dad said be careful to not go through the hardening of the metal. As much as I sharpen my knives, I sure hope that's not the case

depending on how the blade is heat treated you can, but it should take a lot of sharpening, a lot.

Not likely...most mfgs and knifemakers heat treat and temper the entire blade and more often than not the handle also. If you're using a belt sander or grinder to sharpen you have to be very careful not to over heat the steel using a quench tub frequently. That is about all that would change the temper of a blade. If the blades were not heat treated or tempered properly at first..that could give you problems also.

I agree 100%.

That could also happen on a hamon if they have the clay too far down on the blade, or some makers like to only do an edge quench but normally the quench line is well defined.
Some newbies can over heat part of a blade doing a secondary bevel and sell it anyway.. if the blade has even turned a little blue it's got too hot and lost the temper.

Usually if you notice less edge retention than before it means the edge has been detempered due to excessive heat on sharpening. If this is the case it will be a very localized detempering which means if you go a little further you will get beck to the original temper as long as heat is no longer a factor. I do this by sanding a little further with a ceramic belt quenching often.

These are Schrade Green handle Fillet knives. Never used a belt on them. I have two Identical knives. One holds the edge the other not as well. It's probably the steel in the second knife has a different mixture. Thanks for responding.

How long have you had them. At one time Schrade knives were very good, with the ones made in China not so much.

The green handled USA and usa+ (high carbon?) ones are great.