Braze stainless steel tube to a steel plate with SSF-6 silver solder. The resulting bond is a super strong 70,000 psi.
Always preheat your metals when brazing or soldering. (When using large or thicker steel or stainless steel you may need to use oxy-MAPP gas, oxygen propane or an oxyacetylene torch. )
Heating adjacent to the work area will slow down the surrounding area from pulling heat away from the joint to be soldered. When the metals start to change color, apply the flux and continue heating until the metals turn red, then apply the flame to both the parent steels and allow the rod to flow the SSF-6 in to the desired joint.
SSF-6 finishes beautifully, without a need for grinding or machining, and can be applied with a propane, oxy-acetylene, or MAPP gas torch.