Strange Tang Discoloration

I'm working on an Imperial, and have come across something strange.

Before (It's the middle razor)
http://i81.photobucket.com/albums/j2.../Imperial2.jpg


Current State:
http://i81.photobucket.com/albums/j2...g/IMG_0514.jpg
http://i81.photobucket.com/albums/j2...g/IMG_0515.jpg
http://i81.photobucket.com/albums/j2...g/IMG_0516.jpg

You can't really tell from the before pic, but there was bad pitting and corrosion on the tang. The strange part is the discoloration starting before the pivot hole. The sides of the razor have been wet-sanded with 500 grit paper so far. The finer I get with the sanding, the more pronounced the discoloration becomes.

Anyone have any idea what this might be? The sides of the blade and all of the tang are perfectly flat, so it's not an angle change that's causing an optical illusion. On the other side of the tang, the discoloration is exactly the same.

Thats probably how deep the blade went into the salt pot when they went to harden it, the rest of the blade was outside of the molten salt, hung there by a wire. Hence the different color, the end of the tang and monkey tail were not treated. If you search for the dovo production video it will show you how they suspend razors in a salt pot and then the guy grabs them with tongs turns around, takes a couple of steps and puts the tong full of razors into an oil bath to quench. Great vid, worth watching.Again and again and again and......

Thanks for the info. I had a feeling it was a heat treat line, but wasn't sure.

Almost forgot, I just cut out some Bocote scales for this one.

Be sure to post some pics when you get her done, hope you saw and enjoyed the dovo video, as a matter of fact I think I'll watch it now.

I haven't watched the Dovo video yet, but will look for it when I get home. I will definitely post pics when I'm finished. I meant to take some good before and during pics, but I just sort of started and forgot about pics.

Looked like a temper line to me as well

Hmmmmmm....... correct me please if I am wrong about this. I have watched the Dovo video several times and unfortunately it is in German.
One person said that they were using molten lead, not molten salt, for heat treating with a quench in oil. It was also said that the blades were first coated in graphite to keep the lead from sticking to the blade.

Just want to get the facts straight.:)

That's right... when you are watching the video you will hear the commentator say "Blei", which sounds like "Bl" + "eye". That is the german word for lead. (lead pencil = bleistift). I can't imagine that using the lead is in anyway good for the heat treat guy's health.

But, yeah... they use lead, or so it says.

By the way, I hear people pronounce "Solingen" so many different ways. Zo-ling-un is it. an S sounds like a Z in this case. the Zo at the beginning rhymes with "sew". And for some reason, Solingen is always windier than anywhere else in Germany in the winter, or so it would seem.


Ben

Thanks for taking the time to respond! It is much appreciated.:tu