I haven't seen steel inserts for aluminum arrows,they would have to make alot of different sizes for aluminum.With carbon they make a 5/16 brass insert that will Blackhawk Vapor,GT,Beman ICS,Carbon Express,thats one insert to fit all these any any carbon with the inside dia. of .246.Then you have the Axis/MFX that will fit all that take the HIT insert.I just don't see a big market for them,and that is usally what it takes for a company to make something like that.And I can imagine if they did it would probably cost at least $20 or more for inserts.