I think the point he is making it that the heat from the welding affects the temper of the spring steel

 

^^^Precisely.

 

Yes, it may, the springs are very treated, but I doubt it changed the composition at all or enough to make a difference.
And...as D said, we welded to the bottom spring, which is not as major as the upper ones.
The stock clamp is riveted on with a large diameter rivet, which also would take away from the structural integrity of the leaf...the way we went in my opinion is nothing as bad as the stock rivet.

 

The welds on the brackets imo really does not change the temper of the steel... For this to occur, either heat treating of the whole leaf must take place or the steel has to get so hot that it would almost have to become molten. The welding technique used was gasless using a MIG welder. I had the voltage/intensity turned down to minimum when welding onto the leaf to ensure the structual integrity of the leaf still existed. We first welded the 2 steel angle channels together with a higher voltage to ensure proper penetration. I felt that welding to the leaf was to just hold the clamp in place, thus not needing deep penetration, similarily the same purpose as the rivets...