Thread: The Great Razor Analysis Project

Originally Posted by Bruno

...When tamahagane is smelted, the tatara master is awake for 3 days, tending the fire, looking at the color and listening to the sound of the fire raging inside.
...
When swords are heat treated, the same applies: the smith heats the blade and judges the color to determine when the blade is ready for quenching.
Of course this takes a lifetime of experience, but it is possible.

Yes, it is, and not surprisingly the quenching of the sword requires a dark room. Some folks learn from their mistakes, some add another layer of technology and say the old way was no good.

After a while the experts really do look like they are not paying attention to any technology. I suspect that's why elements of magic still seem to play about the edges of what some smiths do.

Make sure all this information doesn't get lost Josh.

Originally Posted by Russel Baldridge

Josh, do you judge the temp for heat treating by the color of the steel?

I have never gotten that to work with any consistency, but the magnet trick has yet to fail me. Give it a try if you haven't already.

Russel, have you played around with decalescence-recalescence yet? No magnets needed.

Originally Posted by Russel Baldridge

Josh, do you judge the temp for heat treating by the color of the steel?

I have never gotten that to work with any consistency, but the magnet trick has yet to fail me. Give it a try if you haven't already.

Russel,

I tried the eyeballing techinque for a while, as well as the magnet. The magnet worked pretty well, but I'm getting much more consistent results using a thermocouple and pyrometer in my forge. I can get the blade up to about 1450 F and hold it there to heat evenly throughout without worrying about overheating.

I'm finding that getting maximum hardness out of the quench is largely a function of quenching from the correct temperature, which seems to correspond to 1400 to 1450 F in my forge. Even 50 or 100 degrees too hot seems to make a difference.

Josh

I'd definitely donate a Wapi for this experiment. I want to see how one of them really compares with some of the other razors. I'll keep track of this post as best I can to find out when you want razors sent to you.

Chris L

How's this project coming along?

Slowly. But it lives on.

I have about 35 or 40 blades right now, and I need to make time to prepare them for the different tests we'll be doing.

It turns out that the chemistry department at my alma mater can test for everything BUT carbon, so I'll need to find a lab that can do the carbon content.

We'll have three tests: alloy content, carbon content, hardness. Plus my eyeballing of the grain size of each blade. (That won't tell us much, unless some of the blades have very large grains.

I'm hoping to get several projects off my plate by the end of the month, which will open up more time for razor stuff.

Josh

I once thought it would be cool to have a spectrometer for analyzing steel chemistry. There is one that works off of a spark test. Can't remember the name but they are portable units good for junkyards and scrap sorting, that kind of thing. Sadly, they are setup to assess the alloying elements and then the steel is matched to known alloys. Carbon testing is not involved. So I gave up on finding an easy cheap way of spec'ing steels.

glad to hear it josh - i will have some blades to send you soon...

Carbon certainly can be detected, but since it's so much lighter than the other components the problem I suspect is that you can't do it on the same machine. I suspect that the Prof. who Josh spoke with would have been aware if somebody else on campus would have that capability....
I am not sure that the cheap spectrometers that detect just content that Mike mentions are good enough to quantify the differences in component content we're looking at.

I wonder how much of an interest such a project would be to somebody like Verhoeven (sp?) - of course if they want to do such a project they have the funds to analyze pretty much anything they wish, so they may not have much interest in us providing a bunch of blades.

In any case Mike, you probably have much better idea who may be suitable. In a university setting it seems like an reasonable undergrad summer project.

Originally Posted by gugi

...Carbon certainly can be detected, but since it's so much lighter than the other components the problem I suspect is that you can't do it on the same machine. ....
I am not sure that the cheap spectrometers that detect just content that Mike mentions are good enough to quantify the differences in component content we're looking at.

I wonder how much of an interest such a project would be to somebody like Verhoeven (sp?) - of course if they want to do such a project they have the funds to analyze pretty much anything they wish, so they may not have much interest in us providing a bunch of blades.

As to University based studies, it will take a professor who's willing to oversee the project and agree that it will be useful for the student's career. I have some contacts at UW and ISU that will likely be asked about their level of interest in the near future. I haven't been really eager to use up favors, even on my own smelted steel, because of the setup time and the U's reluctance to allow their tools to work on outside projects.

Part of that is also their ties to industry. Along the lines of "What about this project will improve current razor technology?" Well, we don't make razors like that anymore, except for these handful of guys who are curious about archeometallurgy and make a dozen blades a year. So, you're not talking about 40 ton ladle shots? Okay, next project...

I was looking for a really portable unit to do testing. Most of the really quality spectro units are bench versions. I'd love to know the carbon content dearly, but that is a higher order machine and it will require destructive testing of a representative piece of material. I suppose with a handful of potential scrap pieces that's not a real restriction.

I suspect that even across the same manufacturer, we'll find a lot of variability in each category.

Originally Posted by JimmyH-AD

I have wondered about the temper and content of various razors myself. In the book Hatcher's Notebook a longtime ordinance officer General Julian Hatcher compiled notes on his observations made over the years. Among the topics was the heat treating of '03 Springfields. Some of them below serial # 800,000 were prone to failure and had in some cases caused serious injury to the shooter.

It was found that the workers responsible for the heat treatment relied on the color of the metal as it was being heated and cooled to determine when the correct temper had been reached. After further analysis it was found that depending on whether it was a sunny or an overcast day the temperatures of the metal being heat treated could vary up to 300 degrees using the eyeball method. Afterwards the Armory began using pyrometers and the problem was solved.

I bring this up because I am assuming that the razorsmiths in the 1800s probably tempered by eye so the results will probably vary whereas once pyrometers were introduced tempering would have been more consistent.

Makes sense to me, I know blacksmithing in dirrect sunlight(especialy outside in the snow) it is very hard to judge the heat of the metal. l