Yep it’s a 60° prep angle and yes I do agree with @Dimitri De Spiegeleer that a 60° prep is a better or lower risk prep for mag welding. I was confused with the included angle bit because what else is included apart from the prep. Any way yes I agree. However 45° is fine also. Granted higher LOF risk over 60° but very achievable as I’ve seen lots of times so really nothing to worry about imoOne on the right looks like a 60 degree prep...
The 5mm 45° bevel is a bad idea, I bet the root isn't as it should.
No prep is the most economical solution (and equally good), however whoever decided prep was necessary should've chosen a smaller prep angle.
Used to do a lot of boiler repair work and all single sided full penetration T-Butts were 45 degree inclusive angle, that was according to the WPS, but that’s a bit of a different scenario...
I cannot ever remember seeing any problems with rollers on end plate/roller welds, it’s usually the shaft that gives you the problems...an Asme 1x 6gr would cover that be a bit ott though
i would think a good fillet would be enough on that could counterbore the roller a bit to locate the plates too