See:
That said, if this is to be an actual part, you need to source a piece of aluminum which is suited to this, in terms of stress-relieving, zero casting defects, &c., and the cutting has to be smooth/even/consistent enough not to create areas which differ significantly from other areas which should be equivalent so as to evenly distribute stresses — do you know of a company which can inspect the part after manufacture to verify that it will be suitably safe?