How much extra metal do you all leave on the blade for heat treatment?

I've made a couple knives, both by forging and stock removal, with a couple failures as well, and to prevent warping problems I've left the last couple 1/16" or so thicker than the desired final thickness until after heat treating- that works well but requires a good deal of careful work with a belt sander after tempering to get the final profile right. With a blade longer than the 6-7" I've been doing that could be considerably more work, plus with more complex cross-sections, particularly fullers, just leaving it that thick all around could be impractical. I believe that cutting fullers post-heat-treatment is possible, but undoubtedly harder than making them while the metal is still soft.

At some point I'd like to try my hand at a sword or two - I may need to get someone to heat treat it for me, as my equipment can't handle much over 7" or so just yet - and I'm curious as to how the real smith handle the process. Thanks.

1mm edge thickness should be enough.

if its something that's very thin for a lot of length (like a type f1 falchion where there's a lot of unsupported material in that broadest "belly" of the blade, or a thin cutter like an XIII) I'll go for 1.5mm to be safe.

if its asymmetrical, like a messer or backsword, I'll go for about 3+mm, because if its a homogenous oil-quenched steel, a thinner edge will result in sabering where it warps towards the edge (as the edge cools faster, and contracts faster, compared to the spine).

The more material you leave on, the more you have to take off, but the more room you have for making any corrections. The edge thickness naturally has to be there. Judging by the moat sale blades I've seen, Albion mills fairly close to the final dimensions in the rest of the blade, but in a production environment with a well-controlled heat treating process this probably makes sense when comparing the costs of lots of grinding on one hand verses some time in a CNC Mill and material expenses on the other when there's an issue during heat treatment.

At the other end of the spectrum, Tinker cuts the outline of the blade in the bar stock and then sends what he calls a 'sword blank' off for heat treatment before any grinding takes place, including the fullers.

Like most anything having to do with swords, it's all about trade offs.

Thank you, gentlemen. I apologize for getting back so late - I clean forgot for several days that I had actually posted the question instead of just thinking about posting it, and when I remembered and came back again I evidently forgot that I hadn't hit "post" on the reply I was composing before I had to restart my computer!