Can any tags sustain such levels of heat?
The short answer is no. Annealing furnaces, used for a variety of metals and silicon wafers, typically exceed 1,000 degree Celsius (1,832 degrees Fahrenheit). The most heat-resistant RFID tags currently on the market are TROI Technologies' rectangular WoW-1 tag (which measures 1.5 inches by 1 inch by 0.5 inch), the circular WoW-2 version (measuring 1.35 inches by 3 inches) and the Armored-RFID model (which measures 1.25 inches by 0.5 inch). These ruggedized tags are embedded in a stainless steel case and have a ceramic layer that can sustain temperatures ranging from 500 degrees to 1,000 degrees Fahrenheit (260 degrees to 538 degrees Celsius). They can be read from six different directions, through the metal, thanks to their special antenna design (see Behold the Weldable Metal Tag! and Armored-RFID Tag Loves to Get Hammered). But even these durable tags cannot withstand temperatures of 1,000 degrees Celsius.
—Mark Roberti, Founder and Editor, RFID Journal