Greetings!
Wow, been lurking too much! There are soo many new members! Anyway, I had a quick question:

How would you HT a sort of Rambo IV machete? I am making one because I live in Brasil and am surrounded by junlge, so I need a good chopping tool. I am going to forge it from a leaf spring, darn good steel. I want to it to be quite sharp, but with good edge holding properties comes the risk of cracking. Should I soften the spine a bit? Maybe to a dark blue? The edge itself would soak at 170 to 180 C.

Furthermore, how should the blade geometry look? Do I forge it high-flat with a small secondary bevel? Or do a sort of scandi/convex grind? I was thinking somewhere along the lines of a Gransfors Bruks axe grind...they get pretty sharp.

Thank to all!

Here now and then you can find macheetes really cheap. If I were you I would buy one if they are sold there and try it out. see what you like aboiut it and what you do not like. Reshape the edge a couple of ways and see what works. cut it with a file so you can see how that works and that will give you and idea of hardness. If you like the way it works it will give you ideas on wot to do with your new one. Including how hard you want the edge and spine. It will also let you feel how a handle works and overall size and weight. Have fun

Definitely do a differential temper and if you plan to use it a lot don't make it too heavy!

Edge would be based on how you plan to use it: Heavy chopping---secondary bevel, light slicing longer bevel fading into the sides.

Then uise it and figure out what you want to change on the *next* one!

Thanks guys!
The reason I want to make one is because the ones sold round here are nice and light, but they just wont hold a good edge. I guess, instead of making one from scratch, I might as well modify one of my existing ones. Cheers dudes, and thanks!