ASTM F959 DTI Structural Washers

Elevate your structural projects with our ASTM F959 DTI structural washers, available in plain steel and hot-dipped galvanized finish, with or without the squirt option. We source exclusively from top American suppliers, ensuring quality that consistently exceeds expectations. Bolster your connections for enduring strength and reliability.


Our ASTM F959 DTI (Direct Tension Indicator) structural washers’ line is designed to provide reliable and accurate tension indication for structural fasteners. These washers are available in two types: A325/A325-3 and A490/A490-3. They can indicate the achievement of a specified minimum bolt tension in a structural bolt set and are intended for installation under either a bolt head or a hardened washer.

The chemical composition, compression load, outside diameter, number of protrusions, thickness values, inside diameter, and protrusion tangential diameter values of these washers are defined by the ASTM F959 standard. The steel materials used in their manufacture are designed, processed, heat treated, and protectively coated as specified by the standard.

These washers are widely used in various applications. Type A325/A325-3 are compatible with ASTM F3125 Grade A325 & F1852 and type A490/A490-3 are compatible with A490 & F2280 bolt sets in both Type 1 and Type 3 (weathering) steel. These washers can be installed with the protrusions against a hardened surface like a bolt head, nut, or washer.

Compared to traditional ASTM F436 washers, our ASTM F959 DTI structural washers line offers enhanced tension indication capabilities. They provide a more accurate and reliable way to monitor bolt tension during installation and service life. This helps ensure the structural integrity of fastened connections and reduces the risk of failure.

When it comes to structural washers, invest in the future of structural fastening with our game-changing DTI washer line today.