More corrosion resistant than steel, and almost as strong, these 18-8 stainless steel screws have a narrower head than pan head screws to fit into tight spaces. They’re often used in electrical panels and next to flanges and raised surfaces in humid, damp, and washdown environments, but will corrode if exposed to salt water or chemicals. A deep slot gives you more driving power and keeps the screwdriver from slipping. Length is measured from under the head.

Passivated screws are finished with an extra layer of rust protection.

NAS 721 screws meet National Aerospace Standards.