18-8 Stainless Steel—The choice for wet and outdoor environments, these washers resist rust. However, they won't hold up to the harsh chemicals that 316 stainless steel can.

Black-Oxide 18-8 Stainless Steel—Typically chosen for their appearance, these washers have a dark, matte coating to create a finished look. They resist rust in wet and outdoor environments, but won't hold up to harsh chemicals as well as 316 stainless steel.

Super-Corrosion-Resistant 316 Stainless Steel—Superior to 18-8 stainless steel, these washers won't degrade when exposed to harsh weather, salt water, and most chemicals.

High-Strength 17-7 PH Stainless Steel—Some of the strongest stainless steel washers we offer, these are comparable to high-strength Grade 8 steel. They won’t rust in wet and outdoor environments, but they can’t handle the harsh chemicals that 316 stainless steel can.

Super-Corrosion-Resistant High-Strength Bumax 88 Stainless Steel—As strong as medium-strength Class 8.8 steel and as corrosion resistant as 316 stainless steel. These washers are commonly used in demanding environments, such as marine and chemical processing applications.

Super-Corrosion-Resistant High-Strength Bumax 109 Stainless Steel—As strong as 17-7 PH stainless steel and as corrosion resistant as 316 stainless steel. These washers are commonly used in demanding environments, such as marine and chemical processing applications.

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

Zinc-Yellow-Chromate-Plated Steel—With the same corrosion resistance as zinc-plated steel, these withstand occasional exposure to moisture.

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

Blue-Dyed Steel—These metric-sized washers have a distinctive blue color, so you can easily tell them apart from inch washers. The coating provides only minimal corrosion resistance, so these washers are best for dry environments.

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

Corrosion-Resistant Galvanized Steel—These washers combine the strength of steel with the rust resistance of stainless steel. They're an economical alternative to 18-8 stainless steel in wet and outdoor environments, but they won't hold up to salt water and chemicals.

Black Super-Corrosion-Resistant-Coated Steel—Combines a finished appearance with the rust resistance of 316 stainless 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.

For Fastener Strength Grade/Class—If you require screws or nuts with a specific fastener strength rating, make sure your washer matches the grade or class.