Zinc-Plated Steel—A step up from plain steel, the zinc plating withstands occasional exposure to moisture.

Black-Oxide Steel—Typically chosen for their appearance, these nuts have a dark, matte coating to create a finished look. They offer minimal corrosion resistance, so they're best for dry environments.

Black Corrosion-Resistant-Coated Steel—The coating has been tested to extreme standards, including 1,000 hours of salt spray resistance, to hold up in wet and outdoor environments. Also known as black luster.

Steel—Best for dry environments since moisture will cause these nuts to rust.

Material Certificate—Nuts include a report with a traceable lot number and a description of their chemical and physical properties.

Zinc-Yellow-Chromate-Plated Steel—With a more durable finish than clear zinc plating, these nuts are suitable for most wet and outdoor environments. However, they won't hold up to the harsh chemicals that stainless steel can.

Black Corrosion-Resistant-Coated Steel—The coating has been tested to extreme standards, including 1,000 hours of salt spray resistance, to hold up in wet and outdoor environments. Also known as black luster.

Zinc-Plated Steel—A step up from plain steel, the zinc plating withstands occasional exposure to moisture.

Black-Oxide Steel—Typically chosen for their appearance, these nuts have a dark, matte coating to create a finished look. They offer minimal corrosion resistance, so they're best for dry environments.

Hot-Dipped Galvanized Steel—Combines the strength of steel with the rust resistance of stainless steel. These nuts are an economical alternative to 18-8 stainless steel in wet and outdoor environments, but they won't hold up to salt water and chemicals. The galvanized finish is thicker than other types of coatings, so the threads may be more likely to stick during installation. Use with other hot-dipped galvanized fasteners.

Steel—Best for dry environments since moisture will cause these nuts to rust.