Let me see if I got this right. You want to enter a particular alloy grade (e.g. 12L14, 1018, etc.) and then calculate some equations using the value for SFPM that it looks up, right?

Yes, exactly. I think you've got it! I want a list of metal alloys to be selectable from a drop-down list. That way my end users will merely choose their metal alloy by the names that they are familiar with. But since a formula can't know what the SFPM number for that alloy is, I would like (if possible) for a number to be somehow automatically associated with the particular alloy the user chooses. So that way, the user's alloy choice will "trigger" the correct SFPM number to be used in the formula for RPM calculation.