How many grades of silver solder are there and what are their melting temperatures?

There are four different silver solders. They are: hard, medium, easy, and easy-flo. Melting temperatures for these solders are: Hard â?? 773 degrees Celsius, Medium â?? 747 degrees Celsius, Easy â?? 711 degrees Celsius, and Easy-flo â?? 681 degrees Celsius.