Temper of Mainspring Guide?

[milesc2]

I have a question for all the experts here:

I am in the process of making a mainspring guide for my baby Luger.

Instead of forming a new hook on the end by hand I have elected to cut a section out of the guide and get it micro tig welded back together.

I dropped it off at my welder tonight and was wondering if I should temper it when he is finished?

If so how exactally? I have tempered small parts in the past but want to make sure I get this right.

Here is a photo of the guide before welding. I believe he is going to grind the edges of the cut to get a full pen weld.

Thanks to all who respond!