Stop in for a cup of coffee
OK, got the answer... This is a Lock-n-stitch fastener.
It actually pulls the crack together when tightened. They can be used without any weld required.
OK, got the answer... This is a Lock-n-stitch fastener.
It actually pulls the crack together when tightened. They can be used without any weld required.
The thread design is what makes them work.
As I understand it the original use was oil field repairs where they could not weld. If done completely overlapping they are supposed to seal the crack 100%. I guess the weld is more like caulking it shut than structural.