Bolsters for what exactly? Folders? Full tang? Hidden tang?
Very amateur here, so please take what I have to say with a grain of salt. I found it too soft for the pommel of a puukko bolster I was fitting, the steel was mushrooming and deforming the hole in the copper when I was peening it, so it never fully got tight. Maybe I hit it too hard, maybe the steel wasn't soft enough.
I do know, however, it scratches pretty easily.