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It would take very large carbides to give that kind of misleading hardness value. The small carbides in Cruforge V are not large enough to seriously change hardness readings. I'd say if you're looking for a certain hardness, just walk the temperatures up to it.

Looking at your grinds, I have a question. Are you using a sled grinding jig? I have used one before and got nice straight grinds, but the tip seemed a little narrower than the plunge area, similar to what I think I see on yours. It could also be an optical illusion. If your tip grinds...

I've been waiting for this to pop up somewhere. How, if at all, does the need for uniform grain size relate to the notion that an array of grain sizes is needed for the highest performance levels, particularly in low alloy or plain carbon steels? I have seen the array of sizes pushed as every...

If you're happy with the performance, then that's great. If you're after just a little more, and what knife maker isn't, you might try heating it just a little higher, like around 1475-1500. The magnet test is just at the fully austenized temperature for 1050 in ideal circumstances. Lower...

Assuming everything else is spot on, and the hardness tests were done accurately (level surface, fine finish, etc), it sounds like your spikes have a carbon content in the 0.4% range, maybe a tad higher. Yes, they should be tough as nails. I always wanted one, but whoever said they were heavy...

Yes for this blade it looks like the delay from foil is the culprit. Still, shrinking grain size has some disadvantages. It would harden, but maybe not the way you want.

Ironically enough, in this case it can hurt. I'll explain in a moment. First, how do you know it didn't harden? Did you hardness test it? Where? If on the handle or full thickness spine for a 3/16" thick blade, you may well be right. Vegetable oil is going to loose you some hardness from...

With either the torch or the forge, how are you judging the temperature to quench?

Have you only tried torch hardening?

Hardness will decrease with time, and the rate is related to the tempering temperature, though it's not that big a deal. Going from 1 to 4 hours only lost 1 point in hardness on some much simpler steels than 154CM. Unless you were tempering at 900-1000 degrees F, you should be fine. And even...

How far do you flex it? To decrease the chance of taking a bend, increase the hardness (strength). However, 0.125 might be too thick. It depends on how far you expect it to flex. Also, 14" blade or 14" overall?

The Leeb scale hardness tester is not good for knives, or anything that thin, without careful coupling of the part to a heavier piece. They are intended (and we used them) for thick sections that cannot be moved to the lab, such as pressure vessels, heavy structural steels (thin beam flanges or...

I always wondered about the warnings to never quench after tempering. I read them jn a couple ofknifemaking books. It made me wonder why such a moderate quench would crack something that just survived much greater temperature swings, rapid cooling, and at least one phase change.

There was some discussion that quick cooling (water quenching) after tempering could improve toughness for blades used in cold conditions. I'm pretty sure it was a general statement in the following context. It might help some steels in some applications, it won't hurt other steels, and it...

So Ed you're soaking for the 52100 core at 1375 to 1425 F? Why are you against soaking?

Ultimately you'll just have to try and see. That said, if you air cool the blade, the A2 should expand while the other portions would already be in pearlite form, thus ductile enough to take some movement. It all depends on how good the weld is, how thick the portions are in relation to each...

Measuring hardness on top of a carbide won't generally get a reading from the carbide. It will just be pushed into the matrix, which is much softer, and the carbides are MUCH smaller than the diamond penetrator used for Rc testing. In a steel like W2, I don't know how you'd make a carbide or...

The outer limits of any test equipment are generally to be avoided, either high or low. Handheld testers are very persnickety in their use and are not accurate on thin sections. Some of Aldo's steels require extensive normalizing to get things to behave. Though it's generally considered to be...

If you're using a torch, you may have to do lots of trial and error. The austenizing temperature for 4140 will be considerably higher than for normal blade steels. Undershooting the austenizing temperature will leave you with soft ferrite in the edge, which no amount of tempering later will...

I have the feeling there is a trick to the Kings that I haven't learned. I did return one and exchange it. It felt like honing on cobble stones.