I have a peace of aluminum that I want to mill out to replace some parts on my router.

It is 1/4" thick and do not know what grade it is, Got it at the recycle and it is harder than a lot of the other aluminum I hove got there before.

The peace to be cut is just a simple rectangle peace with a few holes in it.

Will be using a 1/8" up cut flat tip milling bit.

Would like to know what would be a good cutting dept and speed to do it.

Right now I have it set up for 20" a min. with six passes at .040 each pass.

Need advice if the set up will work or do I need to change it.

There is no cooling or oil for the cut but was thinking about spraying it with silicone spray as I cut it. ????

Thanks
Milton