Tellboy, to be honest I don't know much about the material the saddles are made of, but I do know it's an old ABR1 bridge unit. They are very hard and I don't experience any lack of tone or sustain, and the bonus is that I don't break as many strings as one the '57 R.I. It also has some older Grovers which still in good order. The one thing it does need is a new nut, I reckon by the end of the year it will be due. I had the guitar off a mate who was a guitar store manager who hit some hard times just at the time I sold my '59 R.I so I snapped it up.