Is there a typical range for the measurement of the radius at the junction of the shoulders and tang? I have a Windlass blade that looks to be closest to a type xiii. It has some meat to the tang close to the blade but it is so skinny and soft closer to the threads that I can bend it by hand. My plan is to cut it down for a xiiib by removing the weak end of the tang and gaining the balance of tang needed by taking about an inch and a half from the base of the blade. A search of the fora led to excellent advice on making the cut but I would like the radius to be inside the historical range, particularly for the type. Can anyone help with this or do you just eyeball it?

I have high hopes for this project. I looked around the workbench and found a lot of bits that will only need some modification to make a sword similar in appearance to the xiiib from the Severance collection in the spotlight section.

I can't give you a historically accurate answer, but I assume this might vary from maker to maker, time period and region from no radius at all to a small or medium radius ?

Since the radius is going to be hidden from view by the guard and handle why not go for the best structurally sound radius that might be greater than historically correct ?

As far as I can say, and this is just opinion: A larger radius is probably stronger than a smaller radius, but a 90 degree angle corner without any radius at all does guaranty a stress riser making for a poorer design structurally.

I would at the very least have a 1/16" radius or a 1/8" radius and that should at least be sufficient to avoid creating a stress riser.

Is more than this worth it ? Or does it make more than a minimal and theoretical improvement ? I'm not an engineer and I don't have the math skills to quantify it.

I'll ask a creppy question: As you look at the blade, what radius says to you "I will not shatter"?

That's the right radius.

No, that is not a carefully crafted mathematical answer - I suspect there ISN'T one. Blade thickness, width, taper, probably length, and blade hardness in this area, would all need to go into an equation at the same time.... and I haven't found that equation :).

What we DO know - nasty right angles, with no "give", are a bad idea... they often result in failures at the blade-tang junction. A slow curved taper results in FEWER failures (note - not ZERO failures... if you find a sword with ZERO failures? I will pay you a LOT of money for that sword). Sadly, this is an area where Physics and Art fight it out with each other....

If in doubt - as a good guess? I would copy the radius used in the HT blades. These are very good, very sound - and have gone thru a pretty fair amount of field use. Sometimes, the only GOOD answer comes from actual production units...

Thanks, y'all. I arrived at a similar conclusion after looking at the blade for a while. The radius of my dremel sanding drum looked very generous and led to the easiest method I could employ. The finished work looks pretty sturdy to me and is beefier than most factory Windlass radii I have seen. Fingers crossed but I think it should work.