AN Weld on fittings.

[Brad93]

How are you meant to fit these AN 6 fittings? They have like a double step. What I ended up doing was drilling a 18mm hole then countersinking to get it to fit flush.
The central step is 12.5mm diameter, outer step is 19mm. Overall diameter about 22mm.

@hotrodder

 

[zzr1200]

I've usually seen those fittings welded into the ends of pipe or manifolds.

So the small diameter slides inside the pipe to locate plus support the back of the weld pool, then a root tig and a capping run probably, is the way I see it.

 

[Jim Davey]

I'd guess you can drill any size hole you like? Looks like the steps might make them an easier for into a few different pipe sizes for making fuel rails etc.

 

[Brad93]

Right I get you.
It's just a bit weird because if you drill a 12.5mm hole you put the first step in then you are left with a void underneath the main outer diameter that in my mind would leave a bad joint because there is no way you'd penetrate all the way down into the root on the gap with AC

 

[Jim Davey]

Drill a bigger hole so it drops into the last ridge.

 

[Brad93]

I couldn't on this occasion not enough space. I could weld from the inside too though so it will be good joint. (Ford Racing Puma sump)