DIN434 Double Grooved Square Taper Washers

DIN 434 Double Grooved Square Taper Washers are designed with a tapered profile to provide a more suitable bearing surface where standard flat washers cannot sit evenly. The square shape provides a broad contact area around the fastener, while the taper helps compensate for the inclined surfaces commonly found on structural steel sections. This allows the nut and bolt assembly to maintain more even contact with the washer rather than bearing against an angled surface.

The double-grooved design is an important feature of the washer. The grooves form part of the washer’s characteristic profile and help identify the DIN 434 configuration, while the tapered body provides the functional advantage when fastening through inclined or sloping steel surfaces. This combination makes the washer different from a conventional flat square washer, which is intended for relatively flat bearing surfaces. DIN 434 washers are commonly used together with structural bolts and nuts on steel sections such as I-beams, channels, and other profiles with sloped or tapered flanges. By placing the tapered washer between the nut or bolt head and the inclined surface, the connection can achieve a more appropriate bearing interface without requiring the steel surface itself to be machined flat.

Specification:

DIN 434 washers are steel square taper washers developed for structural bolting on U-sections. Their dimensions are matched to the corresponding metric bolt sizes, with the tapered profile providing the required seating geometry for inclined flanges. The standard covers sizes from M8 to M27, while the washer dimensions include the hole diameter, square dimensions, taper-related measurements, and thickness.

For standard structural applications, carbon steel is the primary material choice, typically supplied with finishes such as plain, zinc plated, black oxide, or hot-dip galvanized depending on the required corrosion protection. Stainless steel versions such as A2 or A4 can also be supplied for applications where corrosion resistance is more important, although they are less typical than steel versions for conventional structural steel connections. Public product ranges likewise list steel as the standard material and stainless steel as an alternative.

Dimension Chart of DIN434 Double Grooved Square Taper Washers:

The DIN 434 dimension chart defines the geometry of the square tapered washer, including the central hole, square outside dimensions, and washer thickness. The tapered profile is particularly important because it determines how the washer seats against an inclined structural-steel surface, while the square outside shape provides a broad bearing area for the nut or bolt head.

The available dimensions are matched to the corresponding metric bolt sizes, with the standard covering M8 to M27. When checking a size, the bolt diameter should be considered together with the washer’s hole size and outside dimensions to ensure adequate clearance and bearing area. The taper and thickness shown in the dimensional drawing are also important for achieving the intended seating position on the steel profile.

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