We believe you already have a fair understanding of aluminium casting. In order to form an aluminium casting, a mould of the part should be first created. This is achieved by pushing the pattern into chemically bound sand which leaves the impression of the casting part. Upon the completion of the mould, the molten aluminium is then poured into the mould and then cooled and hardened. The solidification of molten aluminium is followed by the removal of the mould resulting in the desired part.

How billet aluminium is made is totally different. To understand how it is created, we first need to know what a billet is. It is a solid aluminium (or other material) block whose size depends upon the desired part’s size. The bigger the required part, the bigger the billet. Billet, in contrast to castings, are made by eliminating the excess material out of the billet. Basically, the part is formed by carving out of solid block of aluminium. Though there is no difference between the two methods in terms of the exact part produced, each technique has its own pros and cons. 

The advantages of billet include rapid lead times, high precision levels, cost-effective in smaller quantities and stronger parts structure-wise. Disadvantages include increased costs with increase in quantity, few designs not cost-effective to machines, and some designs not able to be machined out of solid billet.  

The advantages of casting are many: cost effective in bulk quantities, production of parts of several sizes and capacity to make one-off shaped parts. The disadvantages include metal defects or imperfections, uneven surface finish and labour intensiveness.