“I live in Europe, but the exact same insulators are sold here. They are great. But, at least for me, screwing into freshly cut black locust posts resulted a year later in many of the posts splitting longitudinally along the line of the insulators-- they acted like splitting wedges and the internal stress of the post from drying released there. So now I pre-drill holes when they are going into freshly cut, e.g. green/wet posts to prevent that problem. It is also possible to use these in concrete posts, if you first drill with a hammer drill a hole just slightly smaller than the external diameter of the threads, and put in the hole some glue (i used polyurethane) and then screw in with the drill/driver attachment. I only have 9 months on fence done that way, but they seem to hold really tight without problem.”
