Aluminum Ingots...?

When casting aluminum I adhere to the silicon alloys used in the manufacture of engine blocks and cylinder heads and sometimes use automatic transmission cases.

Silicon (Si) 4xxx – The addition of silicon to aluminum reduces melting temperature and improves fluidity. Silicon alone in aluminum produces a nonheat-treatable alloy; however, in combination with magnesium it produces a precipitation hardening heat-treatable alloy. Consequently, there are both heat-treatable and nonheat-treatable alloys within the 4xxx series. Silicon additions to aluminum are commonly used for the manufacturing of castings.