Blackening Aluminum Without Anodizing

I am beginning to think the time required to turn 5/8" carbon steel down to 10-32 diameter is too long.  Because it does not need to handle either a dynamic or static load that would stress aluminum, I might turn down a piece of 1/4" aluminum and attach a 5/8" diameter head using a left hand screw.  Aluminum cuts so quickly that it would be no time to make these.  There are several room temperature blackening agents for aluminum like Insta-Blak.  Anodizing looks to be more equipment to do than I want.