It took to cut steel pipes from the old fence away from the mains. I went off with a hacksaw, tormented myself, spat, and returned.
I decided to try putting a 125 disk on my gas trimmer. There was a disk without problems, without alterations and generally without unnecessary details. You only need a nut from the grinder, which presses the disk. Of course, your brushcutter may be structurally different, but in general they are all very similar.
My disk is centered using the braid clamping nut, which clearly goes into the groove of the nut from the grinder. Look in more detail at a photo. There is no beating, the car cuts like a beast, I did not notice the performance worse than on the grinder, but it is still quite convenient if you need to saw off a vertically protruding object.
Theoretically, you can try to put larger disks, but I couldn’t find one on hand. Good luck