Source: National Precast Concrete Association, Carmel, Ind.
In light of manufacturing and product tolerance differences among precast hardware sources, the NPCA Technical Committee cautions members on the use of multiple coil insert, nut, rod and bolt brands.
“A coil insert from manufacturer ‘A’ and a coil bolt from manufacturer ‘B’ could create a potentially catastrophic result under lifting or handling conditions if coil bolt threads are too loose in the insert or the threads are too tight between the coil bolt and insert. Likewise, using a coil nut from manufacturer ‘A’ and a coil rod or bolt from manufacturer ‘B’ could result in a similar situation,” a late-October NPCA member alert notes.
The association plans to work with stakeholders to address the absence of coil hardware manufacturing standards, but stipulates: “Standards development takes time, so we are recommending that users of these products purchase coil devices from a single source or have a quality system in place to validate the proper engagement of these threaded devices.”