Bronze

Bronze is a material added and used by many various mods. Thermal Expansion adds it under the name Tinker's Alloy.

Engineer's Toolbox
Bronze can be used to make a Socket Frame. Other then that, it isn't very useful. It's created within a Multi Smelter.

Forestry
Bronze Ingots can be made in Forestry by combining 3 Copper Ingots and 1 Tin Ingot in a Crafting Table:

GregTech 5
Bronze dust can be created by combining 3 Copper dust and 1 Tin dust in the Crafting Table. This recipe is considered inefficient due to the ratio of materials:output being 4:3, which is 25% loss of materials.

Using a Mixer to combine the dusts is more efficient.

Bronze can also be created by combining ingots and/or dust in the Alloy Smelter. This recipe is considered more efficient than the shapeless crafting recipe, because it has a 1:1 input:output ratio, providing no loss of materials.

The Copper can be replaced with Tetrahedrite although this is less efficient.

IndustrialCraft 2
Bronze Dust can be made in IndustrialCraft 2 by combining 3 Copper and 1 Tin Dust, Crushed or Purified Crushed Ore. Ingots can be acquired by smelting the dust.