So do none of them fit? Im sure those gaskets vary greatly in quality/size, i would clean the od of pipes where gaskets go with some sandpaper etc& make sure there are no burrs on the pipes same for the inside diameter of new gaskets, also measure gaskets vs pipes,to confirm you got the correct size otherwise you can use a small block of wood & small hammer to get them started but do apply much force, they should go on snug but you should not have to hammer them on,if they do not go on without force you may have to sand the id of the gaskets lightly to get them to fit, also check each gasket to each pipe as one may fit one pipe better than another, depending on tools avail you can also try cooling the pipe& heating the gasketHello all I just bought copper exhaust donuts and i cant get it to go all the way to the end of the exhaust joint. was wondering if there is anyway i can get it all the way in without damaging it