Perfect, you get [ITEMS_WEAPON]! YOU get [ITEMS_WEAPON]! EVERYONE GETS [ITEMS_WEAPON]!
Eh? If that isn't what you want, then you could make a custom workshop, add a reaction class ([REACTION_CLASS:ITEM_METAL]) or something, and do the above steps as pufferfish said.
[NAME:make short sword out of any metal]
[BUILDING:SMELTER:NONE] <-- use any other workshop here if you wish, but let's make it from smelters
then slap [PERMITTED_REACTION:METAL_SWORD] in your entity raws. Upside of this is that the metals are purely limited to your race. Downside is that if you're not going to specify any metal, going for the REACTION_CLASS method instead, you will have a hard time forbidding metals to produce your specific weapon. You can specify a material directly, but this leads to too much clutter.