TRYGG chain for fish farming (grade 64) is certified according to Norwegian Standard NS 9415 and the proposed 9419. The chain is galvanized in two alternative processes, HDG hot dip galvanizing or (TRYGG Aqua) thermo galvanizing. In both processes we produce a chain completely free from inner tensions galvanized at +100my. The chain is 100% secured against HIC and SCC (see chapter on fishery chains).
The hot dip galvanizing is performed in steel tub with a zinc bath holding only 450°C not to reduce the strength more than necessary. At the outlet the chain is continuously moving to prevent the links from being glued together when the zinc layer is hardening. A special ash filter scrubs the surface to keep it smooth.
TRYGG Aqua is galvanized in a rotating furnace at less than 400°C where zinc powder sublimates and the following zinc gas rects with steel surface of the chain to give a layer of ferrozinc. This surface becomes super hard and just as smooth as the chain surface itself. The corrosion resistance is second to none and the wear resistance the same. The surface is well suited for painting or other extra surface treatments.