I had these 10 parts (half of the total rear suspension) printed for total cost of around $200. I'm not sure what percentage of the part is actual brass, I will weigh the spring hangar and figure out density, and compare. They are heavy so I would say they are mostly (if not 100%) brass. I ordered some brass flat stock and it arrived today, so I cut and bent the lower leaf springs. I am not a machinist and this was my first time bending metal. Took me a few tries but I'm pleased how they turned out. They still need a little bit of finishing.