One good tin is that they are inexpensive and will cook your shirt off and melt 55 heavy wall just as fast as I typed this message........in fact it will work 80mm as well if you hand can turn it
Down sides
1)The tip demands compressed air or it will slowly melt together.
2)You better have liquid O2 or you will need at least 3 500t tanks per week.
3)The center fire is touchy
I had one.......used it maybe 8 times and sold it for I never used it much.
~Now a 50mm HA Zenit sits in its place