you could try to let the screw look out of the pipe a little on both sides and then hammer it down to create a solid bolt.
hope you know what i mean. havent tried it out yet, but i think it will flatten out.
it wouldnt even have to be a screw then, you could use a nail or something.
if there are no sharp edges after, you wouldnt even need the tape.
i think im gonna try to build some metal chucks like that soon.
thanks for the inspiration!
/screw me looks like u didnt use a screw but a nail to begin with^^