Due to most bronze swords being cast, how did early iron age black smiths create the tools necessary for smithing / forging iron?
The problem i see is that iron is not cast but hammered into shape, thus requiring tongs,hammers.... which of course must have had to of been made; some how. As well as this, bronze itself would have been to soft to use (or only usable for a short period) as hammers and/or tongs, and the use of stones would be limited to hammers thus, have bronze forging tongs ever been found? and more to the point; are they even feasible / possible? and if not, how did they forge iron smithing tools?
You have to keep in mind that bronze is always an alloy, and iron in any usable form is an alloy as well. Bronze is copper/tin/lead. Bronze used for weaponry would be around 90copper/10tin, and increasing the amount of tin will make the bronze harder, but more brittle (high tin bronze is commonly used for bells, for example). I am unaware of what mixture would be used for making tools unfortunately, though I suspect it would be similar, if only a bit more tin. Iron is worked into a usable form by combining it with carbon to make steel, although iron can be combined with different materials for other results (add oxygen for rust). Properly made bronze is much harder than iron itself, and harder than some low carbon steel, and would have been more than adequate for toolmaking.
The bronze vs iron(steel) conflict is nuanced then. Iron(steel) eventually won out as a material for tools/weapons because of a number of advantages. Iron is much more plentiful than copper and tin. Steel can be welded, is lighter than bronze, and if properly made is stronger. Bronze is still useful in that it will not rust, but not for much else.