Medium-Strength Fastener—Your go-to screws for fastening most machinery and equipment. They have tensile strengths from 90,000 to 120,000 psi.

High-Strength Fastener—Commonly used to fasten components in valves, pumps, motors, and other high-stress applications. These screws have a tensile strength of 125,000 to 160,000 psi.

Zinc-Plated Steel—A common choice for areas with occasional exposure to moisture.

Zinc-Yellow-Chromate-Plated Steel—With slightly better corrosion resistance than zinc-plated steel screws, these stand up to more frequent exposure to moisture.

Steel—Unfinished steel screws are best for dry environments, since moisture will cause them to rust. They require little surface prep before applying a finish, so you can apply your own paint or coating.

Dyed Steel—The distinctive blue color makes it easy to tell these metric-sized screws apart from inch screws.

Zinc-Flake-Coated Steel—The coating is tested to extreme standards, including at least 720 hours of salt spray resistance, to hold up in wet and outdoor environments. An embedded lubricant makes these screws easier to install than corrosion-resistant-coated screws.