Hexagon head screws ISO 4017-5.6 fully threaded yellow zinc A2C M 16 x 25 mm - 20'000/30'000 pcs. with 3.1 certificate Hexagon head screws ISO 4017-5.6 fully threaded yellow zinc A2C M 16 x 30 mm - 5'000/10'000 pcs. with 3.1 certificate