When you’ve applied the correct tension, these washers release an orange dye as a visual indicator.

ASTM F959 Type A325 washers are designed for use with A325 structural screws, studs, and nuts and are often used for construction and exterior building applications. They’re not for use with higher tensile strength bolting. Hot-dipped galvanized A325 washers have a thick coating for excellent corrosion resistance.

ASTM F959 Type A490 washers have greater tensile strength than A325 washers to handle more weight and stress. They’re useful for high-weight structural applications, such as roofs, foundations, beams, and scaffolding. Pair them with ASTM A490 bolts.

Class 8.8 washers are designed to support structural screws, studs, and nuts. Use them with DIN 6914 structural hex head bolts and DIN 6915 structural hex nuts. Hot-dipped galvanized Class 8.8 washers have a thick coating that holds up ten times better than zinc plating in wet environments. Since they are strong and rust resistant, these washers are often used for construction and on building exteriors.

Class 10.9 washers are stronger than Class 8.8 washers. Zinc-plated Class 10.9 washers won’t rust in wet environments.