DIN 434 Square Taper Washers for U-Sections

DIN 434 square taper washers are wedge-shaped washers developed for bolted connections involving U-sections, channel sections, and similar structural profiles with inclined bearing surfaces. Unlike a conventional flat washer, the washer has a tapered geometry that compensates for the inclination of the section, allowing the bolt head or nut to bear more evenly against the connection surface. The current DIN 434 edition is DIN 434:2024, which supersedes the 2000 and 2023 editions.

The defining feature of a DIN 434 washer is its square plan shape combined with a controlled wedge profile. The taper is approximately 8%, allowing the washer to accommodate the sloping flange or surface of a U-section. This geometry helps create a more appropriate bearing interface and reduces the tendency of the bolt head or nut to sit at an unfavorable angle. The washers are commonly identified in the market as square taper washers, square bevel washers, or taper washers for U-sections.

DIN 434 covers metric sizes from M8 through M27. The standardized dimensions include the hole diameter, square dimensions, taper-related geometry, thickness, corner radius, and dimensional tolerances. The range therefore provides standardized options for different U-section connection sizes rather than relying on a generic flat washer.

These washers are primarily associated with structural and mechanical bolted joints using channel or U-shaped sections. Their main selection considerations are the matching bolt size, washer dimensions, orientation of the taper, and compatibility with the geometry of the supporting section.