High Temperature Lead-Free Solder
There is some serious fake information on the "Net" regarding "silver solder". ; starting with Oatey ( Home Depot) who flat out lies about what they call "silver solder". The Halstead net site is good. AWS ( American Welding Society) identifies silver solders as having 45 % to about 60 % silver with copper, zinc, cadmium in various amounts.  Melting ranges of 1125 F to 1250 F and must be heated above those temperatures to flow. These  alloys have  AWS designations of B Ag-1 up to B Ag-7.  I would not consider a product to actually be silver solder unless it had an AWS designation.  ( I am using a 1971 ASM reference and AWS may have added designations or even changed their system ).( Irony , I gave my 1987 ASM reference to a local teacher a few days ago because I had not used it in years).