Has anyone seen these SS studs before?

Came across these ASCA replaced anchors while rapping a route the other day. I havnt seen the hollowed out tips on climbing hardware before. Anyone have the beta on them? Guessing it’s driven in with a special tool to avoid smashing up the threads/face of stud...

Hey Gordy!
Strange... The A2-70 nut is certainly stainless... It looks like the oversized Fixe-style nut.  
But I wonder if that bolt could be a threaded nail drive anchor? Something like this https://www.confast.com/product-3-8-x-2-3-8-strike-anchor/

It might be the case that ASCA just replaced the hangers, and the bolt was original.
Location?

Was there a washer?! That little dimple is used to drive the anchor into the concrete. You can use a nail so you don't bash up the threads while hammering it into the rock.

That's a Fixe Triplex 12mm sleeve bolt. They made them with the divot for a bit, but the more recent ones don't have it.

No special tool or any particular reason for the divot, as far as I'm aware.

Greg Barneswrote: That's a Fixe Triplex 12mm sleeve bolt. They made them with the divot for a bit, but the more recent ones don't have it.

No special tool or any particular reason for the divot, as far as I'm aware.

That makes sense, I’m surprised I’ve never seen this model before! 

They're not all that common, and they require a metric 12mm drill bit (which is smaller diameter than a 1/2" bit). If you spot a bolt like this in the rock, it's really hard to tell the difference between a Triplex and a standard 10mm stud bolt (like the Fixe ones, or many other European brands). Who knows, that could have been the point with the divot to begin with - to identify and help market Triplex!