Corrosion Resistant Unistrut Defender Channel and Fittings Offer Performance and Value

Unistrut Service Company now offers a new, patent-pending product line called Unistrut Defender™. Specifically designed for corrosive applications, Unistrut Defender utilizes two proprietary material coatings conforming to ASTM standards A1046 and A1059. According to independent lab testing, the end-result of this coating process is a finish three times more corrosion resistant than hot-dip galvanized products. 

Lab Results

The chart below shows independent third party lab test results comparing Unistrut Defender versus Hot-Dip Galvanized products.  After 3,000 hours of continuous salt spray exposure per ASTM B117, five of the six Unistrut Defender samples had yet to reach the 5% red rust failure criteria.

In addition to outstanding corrosion resistance, Unistrut Defender does not require the use of more expensive stainless steel fittings, and the material offers a unique self-healing surface that minimizes the need to touch up scratches and blemishes in the field.The defender is Unistrut’s first new finish offering in many years and this material is sure to attract market attention because it offers performance characteristics similar to stainless steel at a fraction of the cost.  Although stainless steel is often the material of choice for the most highly corrosive applications, this enhanced performance comes with a significant increase in price.  Contractors seeking Unistrut Channel with greater corrosion resistance than offered by our hot dipped galvanized finish while avoiding the higher costs associated with stainless steel stainless will find Unistrut Defender provides an excellent mix of value and performance.

Technical Notes

Structural performance, including Slip and Pull-Out Loads, meet all Allowable Loads as specified in the Unistrut General Engineering catalog for carbon steels. Please reference the Unistrut General Engineering Catalog for this information. For best performance and cost benefits, we recommend using Unistrut Defender as a complete metal framing system. Placing Unistrut Defender in contact with stainless steel materials will create a dissimilar metals condition resulting in galvanic corrosion. Some red staining may be observed over time on Unistrut Defender parts in corrosive environments. Red staining is superficial oxidation of the zinc/iron ions at the surface and not corrosion of the substrate steel. This is noted in ASTM A1059 section 6.3.

Next Steps

Specifying Unistrut Defender is fast and easy.  Each part in the Unistrut Defender product line is called out with the letters DF at the end of the part number.  For example, to specify Unistrut Defender in P1000, simply note your selection as Unistrut P1000 DF.  To learn more about Unistrut Defender, download our Tech Bulletin or the Unistrut Defender Catalog.  For questions about applications, pricing, or to place an order, contact Unistrut Service Company for additional assistance. "