HS Code (6-digit)
9027.89.••.••
The 6-digit HS code for strain viewers is 9027.89.
The first 6 digits are the same in every country using the Harmonized System; the full 8-10 digit national code (e.g. EU TARIC, US HTSUS) depends on the destination country.
Polariscopes (strain viewers). These measure internal strains in glass (e.g., strains resulting from toughening, annealing, soldering, etc., which might cause the glass to break easily). They consist essentially of a chamber containing an electric lamp, a light diffusion device, a polariser and a polarising telescope. Stresses in the glass are shown as bright iridescences