Steel shaft into aluminum casting

[Dominic58]

First time posting here, I need to press a 1" steel shaft into a aluminum casting,, it was originally a pressed fit. I have tried tapping it back in but only managed to get it in about an inch, I tried heating it with a heat gun with out much. Success so now I'm thinking about cooling the. Steel shaft in the freezer overnight hoping it wil contrract enough to  go in.
Any suggestions?

Thanks
Dom

[dallen]

use something to heat the aluminum up also

[f350ca]

Heating the aluminum will have the biggest effect. Aluminum has a higher coefficient of expansion and you can warm it up a lot more than you can cool the steel. The freezer will only be 50 or 60 degrees F cooler than room temp, but the oven in the kitchen can warm the casting 3 or 4 hundred degrees above the pin.

[TomG]

Yup.

If my numbers are correct, a 1" hole in aluminum will expand about .008" when heated to 400ºF, but a steel shaft will only shrink about .0004" when cooled to 0ºF.

Tom

[Dominic58]

Thanks for all the reply's
I'll put it on the oven for a bit and hopefully it will work.