Over heated blade?

I was recently given a Lennox straight.At first glance looked to be in good shape. But, I thought I noticed some discoloration. So I looked at in the sun light, it looks like a rainbow from the cutting edge to about a third of the way up. Wondering if the blade got to hot during a sharpening process at some point.

Sharpening does not produce heat that can destroy the temper.
Try some polishing compound to see if this is not patina built up during shaves and rinses with hot water.
If that does not remove the discoloration, try hone it and see if it can get an edge, if yes then you are fine, if no then the razor is a toast.

Sounds more like someone tried to heat it up for some reason. Usually that affects the temper and it isn't reversible. If that's the case, razors like that will not hold an edge. However not being able to see it you may have a patina issue. If it shaves goods and the edge lasts then you have nothing to worry about.

I've also seen that type of discoloration from residues of soaps and cleaning agents on the blade. I suppose it could also be from oil, if the blade had been oiled to prevent rust.
It could be that the blade has been overheated, but don't throw it in the trash yet, because it could be something else.

I have actually been meaning to ask something along these lines myself..

I'm asking because of the buffing process when restoring a blade the blades can get hot to touch if your not careful, would that be enough to damage the blade?

Its a little off topic but anyway.. Dose anyone have an approximate temperature that would start to revere\degrade the tempering process that the blades have been through?


As for your question, is this what you have? http://straightrazorpalace.com/class...goldedge&cat=3 the seller of that razor believes that the color on that blade has no effect on its shave ability.. Hope that helps anyway!

never mind, i have answered my own question lol

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Originally Posted by PapaBull

If you can touch it without burning a blister on your finger, the temper should be unaffected. Until the temperature tops 300 degrees, the crystaline structure of the steel does not change. Tempering steel is actually the process of bringing down the initial hardness to a usable level. Here is more information. Suffice to say that unless you really went nuts on your razor, the poor shaving properties you are experiencing are probably the result of inadequate honing. Working a blade over thoroughly usually blunts the edge significantly and I've found it all too easy to quit honing before the blade is actually sharpened completely.

Here's more on heat treatment, tempering and annealing:

To harden most steel it is heated to a medium red or slightly above the point where it becomes non-magnetic. It is then quenched in water, oil or air depending on the type of steel. The steel is now at its maximum hardness but is very brittle. To reduce the brittleness the metal is tempered by heating it to some where between 350°F and 1350°F. This reduced the hardness a little and the brittelness a lot. Most steels need to be tempered at about 450°F for maximum usable hardness but every steel is slightly different.

To soften steel so that it can be cold worked and machined is called annealing. To anneal steel is is heated to slightly above the hardening temperature and then cooled as slow as possible. Cooling is done in an insulating medium such as dry powdered lime or in vermiculite. High carbon and many alloy steels can only be cooled slow enough in a temperatue controlled furnace since the cooling rate must be only 20 degrees F per hour for several hours.

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source: http://straightrazorpalace.com/gener...de-temper.html

Cool. I will give it a try and see how it goes.

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Originally Posted by RHardy

Cool.

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The quote of the day...

;)