Hexagon Socket Head Screws | Partial Threaded | DIN 912 | ISO 4762 | Steel | 10.9 | Black-Oxide M10X85
These screws are made from an alloy steel. Length is measured from under the head. Black-oxide steel screws are mildly corrosion resistant in dry environments. Zinc-plated steel screws are more corrosion resistant than black-oxide screws for use in wet environments. Hot Deep Galvanized - steel screws are 40 times as corrosion resistant as zinc-plated screws . They withstand 1,000 hours of salt spray per ASTM B117.