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