Ok, I need to join two pieces of steel solid rod end to end. They are different diameters. What's the proper welding method for that? chamfer the edges slightly and weld away? What it is, is my free hydro booster I scored, but it had the wrong rod to connect to the brake pedal, with the wrong eye size and everything. So I cut that off, so I have a piece of rod sticking out of my hydro boost unit, 3/8" diameter, then I took my OEM rod from my vacuum booster, which is 5/8" diameter, and cut it down so total length will match original. It of course has the proper eye on the other other, and is the right diameter to seal through the firewall and such. I need to weld them together. My idea was just to chamfer the edge of the smaller diamter piece and weld 'em. But I'd thought I'd check first.