v band?

All austenitic stainless steels are subject to thermal expansion, which is why great care must be taken when welding, even 625. Rigid jigs, proper arc control, and in larger pieces proper stress relieving/annealing are a must.

Mild steel(CR1018) is often used for one piece header flanges as it doesn’t shift nearly as great as your common stainless(304’s, 321’s ext). There are grades of stainless that prevent these matters, but they’re not suitable for this type of application.

And while we’re on this topic use 309(L) filler when welding stainless to mild or mixed stainless components, except 316 which requires 316L or 625(the latter being $$$$$ at about $90 lb for .035 gauge filler).

summit racing recently started selling them as well…

cheap vbands suck… they may look ok but the bolts are usually weak and fuckin snap. shits gay as hell…