Thread: Does steel have a correctable memory?

Sure many metals and steels can be forcibly bent into another shape, but really my question of course relates to razors. Specifically, finished razors rather than razors in the process of being fashioned.

Your typical vintage blade. We've all experienced "warped" blades. I was thinking, if a clamp was made using a few small straight edges sandwiching the edge lengthwise and two more straight edges clamped the spine lengthwise and finally.....some straight edges clamped down both the spine and the edge crossway, would this or a similar concept correct the warp and bring the blade into trueness? Orthodontia for razors with problems.

Or...after removing the clamps, would the steel revert back to its pre-clampning shape?

Chris L

I do not claim to be an expert, so my opinion really means nothing,BUT seeing that razors are made of very hard steel I would think the stress would crack/break the blade entirely no matter how you wrapped it. It might be done if you annealed it first. Dont take any of this to heart, its just my 2c, wait for someone who knows before making a decision.

If the blade was differentially hardened, meaning the back was softer than the edge, your method might work. But if the blade is through hardened, I'd agree with Nun2, it's more likely to completely separate. If the blade is full hard, it likely happened during the original heat treatment. It's amazing that so many blades made it out into the public domain for use in that condition.

When making a new razor, that's why it's recommended to leave things a little thick at the edge before heat treatment. That way if there is a little warpage, at least you can grind the edge straight and compensate.

The real trouble with reheating and annealing "old" razors is that they are already ground down to thin. The heating process can cause scale loss on the surface which will require regrinding and the whole blade will be different than what was started. It could be done, but it's risky even with the right equipment like salt or lead baths and still have something left that looks like the original. But changing the heat treatment means its likely to be a whole different razor even if it looks the same.

Thoughts to ponder.

Agreed, any stress needed to deform hardened steel would be great enough to risk serious breakage. You would need to stress the steel beyond the elastic limit to reverse a warped edge which would require more of a concave clamping mechanism than the flat bars. And to make matters worse, it would be fairly imprecise if it could be made to work since the edge is so thin and could easily be warped into the other direction rather than straight, where you want it.

Stupid warped vintage blades!

I figured as much. Thanks for the info, guys. In a perfect world, all blades that I shave with would lie perfectly flat (on both the front and back side of the blades mind you) on wide hones and be a pleasure and a breeze to hone and maintain. I guess that would take half the fun out of it too, though (substitute "fun" for the word frustration or any four letter word you may choose depending on your mood).

I guess that's that. I will have to eventually make my own shaving implements in which case then my goal WOULD be to have the end result lay beautifully flat on the flat honing surface. Now THAT'S worth daydreaming about!

Chris L

Chris,

I believe steel does have a memory, but it's possible the warp actually represents the steel returning to the shape it was "remembering." I've heard of blades made of straightened coil springs developing a curve when quenched. Not sure if it's true.

One other option for straightening blades would be to soften the back of the blade while keeping the edge cool. You might be able to keep the edge submerged in water and heat the spine with a torch. That would partially anneal the spine and allow you to straighten it.

Probably more trouble than it's worth, but it might be fun to try sometime.

Josh

I'd just like to get something clarified. Chris said "In a perfect world, all blades that I shave with would lie perfectly flat (on both the front and back side of the blades mind you) on wide hones". This is where I became suspicious. If a blade is warped, it must lay uneven on *both* sides of the spine only in the opposite direction. I have a razor that lays perfectly flat on one side and has a straight edge from the factory but rocks all over the place on the other side. I don't consider this blade warped, just very poorly ground on that side that rocks and you can clearly see there is a hump in that side of the spine as well as tell tale signs in the hollow indicating the material is thicker in the same spot. I'm thinking of perhaps getting one of the grindmeisters to introduce that blade to a belt grinder as I'm not the man for that particular job but I'm sure it would be a touchy fix considering it's pretty much a full hollowground blade. I might just straighten out the spine where it touches the hone and live with the uneven blade/bevel that will result. Still, I just wanted to point out that sometimes blades are not warped if they will rest on the hone properly on one side but not the other. A blade that is warped can lay flat on one side but there will be a hollow in the middle portion of the spine and there will be a corresponding hump on the other side that lets the blade rock back and forth in which case the spine will look like a banana from up top.


Christian

Originally Posted by kaptain_zero

I'd just like to get something clarified. Chris said "In a perfect world, all blades that I shave with would lie perfectly flat (on both the front and back side of the blades mind you) on wide hones". This is where I became suspicious. If a blade is warped, it must lay uneven on *both* sides of the spine only in the opposite direction. I have a razor that lays perfectly flat on one side and has a straight edge from the factory but rocks all over the place on the other side. I don't consider this blade warped, just very poorly ground on that side that rocks and you can clearly see there is a hump in that side of the spine as well as tell tale signs in the hollow indicating the material is thicker in the same spot. I'm thinking of perhaps getting one of the grindmeisters to introduce that blade to a belt grinder as I'm not the man for that particular job but I'm sure it would be a touchy fix considering it's pretty much a full hollowground blade. I might just straighten out the spine where it touches the hone and live with the uneven blade/bevel that will result. Still, I just wanted to point out that sometimes blades are not warped if they will rest on the hone properly on one side but not the other. A blade that is warped can lay flat on one side but there will be a hollow in the middle portion of the spine and there will be a corresponding hump on the other side that lets the blade rock back and forth in which case the spine will look like a banana from up top.


Christian

Thanks for the additional clarification, Christian. I agree with you. I have used the term "warped" in this post rather loosely. I own truly warped blades (as you describe them) as well as more blades that are flat on one side and have issues, normally from what I have seen, on the spine of the other side screwing up the edge on the spine problem side from lying flat. Still, in my perfect world, my razors would lie perfectly flat, choruses would sing as I effortlessly hone my razors to sharply comfortable perfection each and every time. Yeah yeah, I know, dream on, Chris.

Chris L

Heh.... in my little warped, but perfect world, each and every razor would have a swayed back, bellied (smiling) edge and require serious body english to hone!

Oh, and to your original question... once steel has been hardened, if you move past the elasticity limit, you are permanently deforming the steel and that means breakage when it comes to hardened steel unless it's been tempered way beyond what razors are normally.

An interesting side point for some, aluminum does not have any elasticity... zero, zip! Yes, you can flex aluminum, but each and every time aluminum is flexed it actually adds to structural failure.... Steel if flexed within it's elasticity boundaries, is not affected and thus we have spring steel but not spring aluminum and this is why stress fractures are a common problem on aircraft where flex is unavoidable but steel is just too heavy to use.


Regards

Kaptain "Booze can cause brain fractures... I think" Zero

Originally Posted by kaptain_zero

An interesting side point for some, aluminum does not have any elasticity... zero, zip! Yes, you can flex aluminum, but each and every time aluminum is flexed it actually adds to structural failure.... Steel if flexed within it's elasticity boundaries, is not affected and thus we have spring steel but not spring aluminum and this is why stress fractures are a common problem on aircraft where flex is unavoidable but steel is just too heavy to use.

I beg to differ on this. Aluminum has a very small elastic region, and steel can be flexed only so many times before it fails from fatigue (normally tens of thousands of cycles, but it will fail eventually)

In the subject of warped blades, I have nothing more to add that was not already mentioned by our esteemed bladesmiths. Once that sucker is teat treated, you're pretty much limited to material removal for shaping. This is not a problem if there is steel where you don't want it, but a major issue if there is none where you do want it.