I spent the afternoon cutting the ends off three 2300 x 100 x 50 x 4mm thick wall galvanised pallet racking beams that I picked up from my old workplace as I'm making a gantry to lift my new lathe into position when it comes.
I set the the two that will be the uprights, individually, in the mill and drilled five 10mm dia holes through both walls to give a width of 51mm, they almost touched but didn't quite. I then went outside and cut down from the end to the two outer holes using my angle grinder fitted with a 1mm blade, the piece I didn't want dropped out just like tearing a stamp off.