Behind the Scenes of Composite Crossarm Testing

Before mounting a composite fiberglass crossarm to a utility pole or starting the design of an electrical grid, it’s important to make sure that each piece of equipment and every component of your utility infrastructure is strong enough to withstand the most extreme conditions and backed by rigorous product testing to ensure maximum reliability.

At DIS-TRAN Overhead Solutions, every composite crossarm is thoroughly inspected by a certified quality control expert to ensure each customer receives a strong, durable product. In this post, we’re going to explain the different elements we test for, why crossarm testing is important, and how DIS-TRAN Overhead Solutions delivers on those standards of quality.

Bending Strength

Composite crossarms engineered by DIS-TRAN Overhead Solutions have relatively consistent dimensions and properties. As a result, loading and deflection measurements are constant and easily tested. Crossarm assemblies are put through rigorous tests that mimic the extreme weather conditions they face on a regular basis. Both tangent and deadend crossarms are tested for bending strength in order to determine their ability to maintain the support of vital utility components.

Each test is conducted to determine the Lower Exclusion Limit, or LEL, which identifies the ultimate bending strength of the crossarms. When the Ultravex®  composite fiberglass crossarm was tested, the result was a 5% lower exclusion limit; meaning that 95% of the crossarm can exceed the ultimate bending strength with only a 5% chance that it will fail under that given load. It’s why utility companies have confidence in our Ultravex®  crossarm product to perform effectively under their loads.

In order to create more transparency around product testing, DIS-TRAN Overhead Solutions and other leaders in the industry are pushing to have all composite fiberglass crossarm companies post their LEL test reportsfor everyone to see.

At DIS-TRAN Overhead Solutions, the products tested are the same products that would be used in an actual assembly which makes it even more important for the results of each test to be precise and implemented into the design.

UV Resistance

Composite fiberglass crossarms are trusted to perform in extreme conditions–none more extreme than direct sunlight for hours, days, months and even years at a time. The extended exposure to UV rays takes its toll on most pieces of utility equipment, which is why our crossarms are tested according to the highest standards of UV resistance and designed for longer-lasting durability.

In a third-party testing  laboratory, crossarms are exposed to accelerated light tests using fluorescent and UV light in accordance with the ASTM standard measurements. This type of test is intended to reproduce the weathering effects that occur when the crossarm materials are exposed to direct sunlight

In the design of the Ultravex® Crossarm there is an outer, UV resistant surfacing veil that is made from Nylon and arranged in a bi-directional formation. Further, the UV resistant fiberglass mat is a random directional, continuous filament mat that is located beneath the veil. Just beneath that, there is a proprietary blend of UV stabilized Isophthalic Polyester Resin that provides additional protection from UV.   


For more information about our crossarm products, the Ultravex® Crossarm and how DIS-TRAN Overhead Solutions can support your utility needs, fill out the form on our contact page.

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