Thread: knife maker making a razor

Originally Posted by AKmik

They are all tempered, weather a manufacturer uses that as a marketing gimmick or not.

Something very common in the SR world is confusion, or misinformation about tempering/HT of steels. I have watched several videos now being narrated by someone in the SR community at a makers shop describing the HT process and he was way off in his interpretation of what goes on. Not a big deal as far as consumers go , but if you were researching processes (me) that is bad info.


EDIT
***** the saying "don't tell fish stories to the fish" comes to my mind here. Hahaa don't think I need to explain HT to you.
Im leaving my answer up for you to educate me here if I am wrong. Just saw your avatar after I replied and thought it looked familiar from the videos.

I am not sure what to say, I speak in the videos, as I understand the process. I feel pretty comfortable with my heat treating process and knowledge.

I am not sure where I am way off in my understanding of things, my thoughts and processes agree with the text that I have read, and the knowledge that has been passed on to me by other more knowledgeable teachers.

Life long learning is one of my core principles, teach me.

Originally Posted by AKmik

Negative, any blade must be tempered to some degree after the quench. A 1095 blade can crack just sitting on the bench if you dilly dally between the quench and temper. You can adjust the HRc (RC) by adjusting the temper temperature.

That's awesome! thanks for engaging in my hypothetical.

Originally Posted by spazola

I am not sure what to say, I speak in the videos, as I understand the process. I feel pretty comfortable with my heat treating process and knowledge.

I am not sure where I am way off in my understanding of things, my thoughts and processes agree with the text that I have read, and the knowledge that has been passed on to me by other more knowledgeable teachers.

Life long learning is one of my core principles, teach me.

Oh , No sorry.

Let me clarify here, not your videos I was referring to. I was not in any way criticizing your work, or videos. This was one made by what sounded like a person from a shave shop, who was did not really understand the heat treat process.

I have been learning from watching you my man. I have been making knives for about 15 or so years, but am very new to making razors. I have been watching your videos and any other out there for the last couple months and reading up here on the board, actually what brought me to SRP. I just started my first batch a couple weeks ago.

What i was saying is that all blades (carbon steels) go from the heat treat oven/forge to the quench , and then are tempered as the final step in the HT process.

I was confused by your post stating that you found tempered razors more comfortable, since as far as I know all steel needs to be tempered after heat treat...

It's hard to debate when generalities are being discussed. AKmik, perhaps speaking of more specific points will help this discussion.

Charlie makes good razors. I know the sources of his heat treatment education. Those are difficult to criticize. But, his razors shave hair, and his customers are satisfied. He meets the first major criteria successfully. Throughout history there have been a lot of blades that were good blades that did not benefit from the HT knowledge we have available today. They are no less good than what we make now.

I have noticed that some schools do not separate heat treatment, e.g. heat and quench to harden, from tempering, e.g. heat to reduce hardness or stress relief, but call the whole process tempering. This is imprecise but difficult to correct in common use.

edited to clarify things.

it's true that even many knifemakers on youtube spout nonsense. I've heard one explain that quenching puts extra carbon in the steel and that's why it is hard.

In any case, while a no-temper hardness is of course harder, the edge will also be prone to microchipping and be difficult to hone because of that. So aside from the fact that microchipping will degrade shaving quality, honing is part of the normal lifecycle of a razor and if honing becomes very finicky, that hurts the usefulness of the razor.

Hence the sweetspot of 59 to 61 which is very hard, has good edge retention, can be honed to a very sharp edge, and is easy enough to hone. Much higher and honing become a nuisance. Much lower and edge retention will suffer.

Originally Posted by Mike Blue

It's hard to debate when generalities are being discussed. AKmik, perhaps speaking of more specific points will help this discussion.

Charlie makes good razors. I know the sources of his heat treatment education. Those are difficult to criticize. But, his razors shave hair, and his customers are satisfied. He meets the first major criteria successfully. Throughout history there have been a lot of blades that were good blades that did not benefit from the HT knowledge we have available today. They are no less good than what we make now.

I have noticed that some schools do not separate heat treatment, e.g. heat and quench to harden, from tempering, e.g. heat to reduce hardness or stress relief, but call the whole process tempering. This is imprecise but difficult to correct in common use.

edited to clarify things.

Mike,

I do want to be clear, I was not criticizing Charlie's work , not at all. He makes a great looking product and his videos are a joy to watch as another craftsman. I have learned a ton watching him work.

You are right , I think its just the wording and the conjoining of the process that had me questioning. hahaa then of course I felt like an ass for questioning the guy who has been showing me how to make razors , but Im good like that.

Bruno,
Absolutely, Lots of bad information floating around on different blade forums and youtube. 59-61 is the sweet spot which requires tempering to achieve, so I believe we are all on the same page.










So

I feel like we need one of those, nothing to see here, lets move along post.

Move along. please.

sooo just to add another hypothetical metallurgical question, because I rarely (see never) have access to people with so much HT and temper experience, what about using 5160? according to the specs its quenched hardness is around 58-62, meaning quenched it would have exactly the right hardness for a razor, and due to the lower carbon content (spring steel ftw) it would keep a more malleable quality. thoughts?

Originally Posted by Boots

sooo just to add another hypothetical metallurgical question, because I rarely (see never) have access to people with so much HT and temper experience, what about using 5160? according to the specs its quenched hardness is around 58-62, meaning quenched it would have exactly the right hardness for a razor, and due to the lower carbon content (spring steel ftw) it would keep a more malleable quality. thoughts?

5160 can get hard enough, but hardness is not everything. The greater amount of carbon in a high carbon steel makes for a more abrasion resistant steel.

I have not made a razor from 5160, but I do not think it would hold an edge as long as a higher carbon steel like O1, or 1095.

Hardness is only one consideration, grain size, and abrasion resistance are also big players in consideration of steel for a razor.