Many NASA inventions have had subsequent lives in the commercial marketplace. Have the Space Shuttle's heat-shielding tiles also had a second life?
Jewelry Design — Jewelers no longer have to worry about inhaling dangerous asbestos fibers from the blocks they use as soldering bases. Space Shuttle heat shield tiles offer jewelers a safer soldering base with temperature resistance far beyond the 1,400 degrees Fahrenheit generated by the jeweler's torch.
There is also:
Automotive Insulation — Materials from the Space Shuttle thermal protection system are being used on NASCAR racing cars to protect drivers from the extreme heat generated by the engines.
But the latter isn't specific about the Space Shuttle heat shield tiles (aka HRSI - High-temperature Reusable Surface Insulation) and I believe they're referring to the use of Reinforced Carbon–Carbon (RCC) composites and Flexible Insulation Blankets (FIB) here. NASA at NASCAR page isn't much more specific on this, but it does list some other NASA Spinoff technologies that benefit the National Association for Stock Car Auto Racing, from fire-resistant materials for race car drivers and pit crew suits to better brakes and safer tires.
There is an additional, indirect benefit to the industry developed for the HRSI tiles:
Product Labeling — NASA needs to identify, track, and keep records on each of the thousands of heat-shield tiles on the Space Shuttle. This required a labeling system that could be put on ceramic material and withstand the rigors of space travel to be readable after a flight. NASA developed high data-density, two-dimensional, machine-readable symbol technology used to mark individual tiles. This novel method of labeling products with invisible and virtually indestructible markings can be used on electronic parts, pharmaceuticals and livestock -- in fact on just about anything.
Source: Space Shuttle Program Benefits Industry and Health. You can read more about this laser-etched symbol coding, dubbed "compressed symbologies", now commercialized labeling / identification system through a NASA Space Act agreement, on NASA Spinoff. I'm reproducing a shot excerpt here for convenience:
Compressed symbologies can withstand extreme fluctuations of temperatures, up to 2,200 degrees Fahrenheit and an air flow exceeding 18,000 miles per hour. That is the heat load and speed associated with a Shuttle orbiter during a space mission.
The coding technology provides up to 100 times as much information as linear bar coding symbology in the same or less space. Markings can range in size from a mere four microns (read microscopically) to as large as two square feet (read telescopically).