Question about mounting seat belts to the chassis....

What is needed to be legal? Seems like 7/16" is the bolt size? Do the metal seatbelt eyelets need to be mount in a single shear setup (eyelet and single tab on chassis)? or does it need to be double shear (two tabs with the eyelet sandwiched between)?

My shoulder harness is a wrap type so I just need to weld tabs for the crotch and lap belts.

If your talking about a solid/tight nut & bolt belt attachment (not the loose/floppy eye-bolt and spring latch tab style attachments) I don't think I have ever seen anyone use a double shear layout (2 chassis brackets/tabs outside holding 1 belt tab inside). Usually it's just 1 chassis bracket/tab holding 1 belt tab (single shear). You do however try to always make sure the belt's tab is bolted to the "inside" driver facing surface of any chassis bracket/tab that could be exposed to and possible guardrail/ground scuffing in a crash. Like if the driver's left side lap belt chassis bracket is welded directly to the main hoop/rocker bar area it's self.

Things might have changed but if I remember correctly there is still no minimum thickness for a chassis bracket/tab for SFI 5 point belt mounting. In the past I have used 3/16" plate if its a mild steel chassis bracket/tab & 1/8" plate if it's a 'moly bracket/tab.

Thanks Dave.