Bronze is an item in Industrial Craft that comes in the form of Bronze dust and Bronze Ingot. This is an alloy made by macerating copper and tin dusts and combining them in a 3:1 ratio to yield 2 Bronze dusts, which is then smelts into ingots. Bronze ore does not exist so it cannot be found in the ground.
It can also be created in Rotary Macerator by placing Copper Ore in the top left slot and Tin Ore in the top right slot. The Macerator will create 2 Bronze Dust and use one Copper Ore each go-around, using one Tin ore every third, as per the recipe. If you pull the Tin ore out early, it will 'eat' one of the ores.
The Bronze Dust can then be smelted into Bronze Ingots.
Bronze also is used to craft the important Wrench (IndustrialCraft), which is used for dismantling machines.
It has an EMC value of 255, which is lower than an Iron Ingot or a Tin Ingot. This is because the EMC for all the dusts added together and divided by two equals 255.5. This was rounded down to get 255, losing .5 EMC per dust. You can use bronze to make items such as minecarts, which use an Iron Ingot's EMC. However, any slight EMC gain is offset by smelting and maceration costs.
Note: Bronze could previously be crafted with Ingots, but as Forestry was removed, this is no longer possible.