Not sure why no one answered your question before, and I don't pay close attention to /r/askhistorians any more.

The Inca did make bronze, continuing a tradition from earlier and other societies in the Andes. However metal throughout the Americas was never really functional. Even when metal was worked into tools or weapons (as opposed to ornaments and jewellery), these tools always had a sort of ceremonial or elite role (think like a U.S. marine's sword; it's not going to be used as an actual weapon, but is a part of the ceremonial dress). This is not to say that bronze and copper were never used for everyday use, but they were not mass produced for regular use. There may be some economic or technological reasons for this, but primarily this is a cultural thing; metal was not seen as an everyday object.

Andean Value Systems and the Development of Prehistoric Metallurgy by Heather Lechtman (1984) is a great source for this; if you do not have access to academic articles, you can get free online access through JSTOR.

This website is a great source for seeing the kinds of artifacts found throughout Peru. Their entire collection is online, and it consists of half a million objects or so. The museum's focus is on the north coast of Peru (far from the Inca heartland and only conquered by the Inca in 1470), but they have stuff from throughout Peru, Bolivia, and parts of Chile and Ecuador.

If you cannot read Spanish, the basics links/boxes you want are: Búsqueda avanzada, then select Inca from the "cultura" box, and then select metal from the "Material" box. This brings up another box and you can select the various Bronce (bronze) choices, or Cobre (copper), if interested. Also, oro=gold, plata=silver, bismuto=bismuth, platino=platinum, plomo=lead.

Ninja edit: ok, that museum does not have a lot of bronze. So nevermind. It's still a good source for lots of things. Either way, the Inca did make bronze, primarily arsenical bronze rather than the tin bronze common in the Old World.