What do you want to do with it? I’ll assume chopper.
Dunno that you will find anything quite as thick as you want, but I’ll echo the advice to take a look at Condor. The 13” Golok is as thick as I have seen, 6mm at the spine with a dramatic distal taper. It is a very good chopper, for a machete. It throws chips like an axe, rather than cutting deep, as a thiiner blade would. A lot of people say it needs a thinner grind to cut optimally. I don’t know enough to judge that, but with a thicker spine, it would be more difficult to get a thin grind.
The Golok also has a pretty heavy feel. The only reason it gets away with being so thick is that the blade is relatively narrow. If the spine were anywhere near as thick as a hatchet, or the tip as wide as a bolo, you might not be able to heft it comfortably.
The Condor Mini Duku Parang and the Pack Golok are more like 5mm. I suspect the other Condor choppers are in that range as well, but you would have to check the spec sheets.
I have been playing with bolos lately. They are thinner, but chop pretty well because of the weighted blade, with more weight concentrated toward the tip. They cut deep on the first cut, rather than throwing chips like the Golok. The Condor bolo may be thicker than my Tramontina and Imacasa bolos, which are around 2mm. My boy has one, but he is twenty miles away so I cannot check it readily. I would expect a bolo of 14-16” with a blade even as thick as 3mm would feel pretty heavy, even if it might chop pretty well.
I’m not trying to talk you out of your exact specs, only to suggest that there may be good reasons you can’t find what you are looking for readymade.