HEAVY GALVANISED CHAIN, 6MM INDIVIDUALLY WELDED LINKS, 4.25 m long
SIZE: 6MM THICK X 35MM L exterior x 22 mm width
WEIGHT: 3.5 kg Galvanised coating worn away on some links which reveals a metal sheen, suspected steel...'
Material may be carbon steel or of chrome, nickel and molybdenum.
Chain bought from a locksmith, not a chain shop, or general hardware store.
Links are not short so assumed not an anchor chain for boaters. Pictured a strong brass lock but with no key available. Locksmith can "re-key' or else shank sheared.