Identification and Advice

[MittensKitten]

I have what I believe is a boys axe head. I think it may be Gransfors Bruks. Can you identify it by the markings? Also I have this scallop shaped hewing hatchet/axe head that I can only make out Nashua NH and what looks like underhill edge tool co. Can you tell me why the hardened steel is curved instead of straight across the blade on the hewing axe and if enough material remains to make it worth hanging and using? Would sanding and polishing these while avoiding the marks be an acceptable way to restore and put back to work? What grit would you use? Would you file or grind down a mushroomed poll? These are blades I regret vinegar soaking and want to do the best thing from here forward. Thanks.

not sure I attached the images properly, lets see... Obviously not attached right..
Trying to figure out the image url issue

 

[MittensKitten]

deleted

 

[Hickory n steel]

I have what I believe is a boys axe head. I think it may be Gransfors Bruks. Can you identify it by the markings? Also I have this scallop shaped hewing hatchet/axe head that I can only make out Nashua NH and what looks like underhill edge tool co. Can you tell me why the hardened steel is curved instead of straight across the blade on the hewing axe and if enough material remains to make it worth hanging and using? Would sanding and polishing these while avoiding the marks be an acceptable way to restore and put back to work? What grit would you use? Would you file or grind down a mushroomed poll? These are blades I regret vinegar soaking and want to do the best thing from here forward. Thanks.

not sure I attached the images properly, lets see... Obviously not attached right..
Trying to figure out the image url issue

The GBA is definitely a Gransfors Bruks boys axe.
I don't know anything about the other.

Personally I don't find shining up a vintage tool to be the way to go, it's your axe to do what you want with but I'd just use a wire wheel to remove the rust.
If there's some thick scaly rust I may take some 220 and target just those areas stopping before I get down to here metal but this is just my method.
My thoughts are that a vintage tool like this should look it while new looking is for things that are new.
A tool doesn't have to look new to work.
For the mushrooming I hammer it back the best I can then file down what I can get hammered back in.

This is just my personal thoughts and methods.

 

[MittensKitten]

Thanks for the advice.

 

[Agent_H]

It might be that line isn't straight because at least one is a harder steel insert instead of a more modern monosteel that has had the end hardened.

I can be wrong and sometimes am.

 

[Square_peg]

Can you tell me why the hardened steel is curved instead of straight across the blade on the hewing axe and if enough material remains to make it worth hanging and using?

First yes, both axes have plenty of good steel remaining to make them worth restoring and using for many years.

As for why the hardened steel is curved there may be multiple explanations for why that shape appears on various axes. One cause is a transition line between a high carbon bit and a low or medium carbon body. Many axes were made this way beause the body and eye are much easier to form out of mild steel. A view from the top or bottom edge might support this cause. Underhills are likely old enough that they were made using an inserted high carbon bit. Later axes usually employed an overlayed high carbon bit or an electro-welded bit.

If the top edge view of your axe shows the dark steel continuing back behind the line, sandwiched between layers of light colored steel then your bit was constructed with an inlaid bit.

But this curved pattern of discolored metal at the bit has also been observed on Plumb monosteel axes. The reason for this not clearly established to my knowledge. I have theorized that this might be due to heat from the thickened center of the cheeks dissipating across the original quench line to change the morphology of the axe. Or possibly the center of the bit (with the highest mass) doesn't cool as completely as the thinner edges and this affects the appearance (and possibly hardness) of the steel.

Forum members with a better understanding of steel then I have stated that there is no reason the mechanisms I've described should affect the axe in this way. But I'm unaware of any other theories having been put forth to date. I would welcome them for discussion.