In preferred embodiments of the invention, {HEAD ~ iron} is mixed as the main component of the material of the spring band clip with {TAIL ~ other elements} in a ratio according to the following table: 
is mixed with
In preferred embodiments of the invention , { HEAD ~ iron } is mixed as the main component of the material of the spring band clip with { TAIL ~ other elements } in a ratio according to the following table :
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL REL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH