3-Question Joining Fit Check

The Joining Access Triangle, as a form. Three answers decide whether your part needs flow drill screwdriving, clinching, self-piercing riveting or spot welding — before anyone quotes equipment.

Question 1 — access Can a tool reach the back face of the joint? Not “is there a gap” — can a die or an electrode physically sit behind the joint and take load?
Question 2 — C-frame room Is there room for a C-frame deep enough to carry punch and die to that face? Hydro-formed tubes and extruded battery frames usually answer no even when a gap exists.
Question 3 — service Does the joint have to come apart for service, repair or recycling? A formed metric thread separates and re-fastens. A clinch button or a rivet does not.