We get a lot of calls about pre-drilling the posts, so that prompts me to address the issue of drilling the posts. So, let’s talk a little about the drilling procedure.
We recommend that you field drill PasturePro posts after they are driven in the ground. They drill quite easily with a standard cordless drill. The posts when driven are very hard to turn, so if you pre-drill them and then get off when driving them your cotter pins will not be square with the fence and cause you some problems.
The cotter pin we provide is 13 gauge, class III. You want to drill a hole that just allows the pin to go through. Do NOT oversize the hole. A 7/32″ or 3/16″ hole is adequate, so please don’t drill a larger hole. If you have some 10 to 12 gauge cotter pins on hand, please just keep them for other uses, and do not use them on PasturePro posts.
You will likely be taking out more material than necessary and hey, its common sense – if you drill a hole thru any rod material, it will weaken it at that point. We have had no problems with the 13 gauge cotter pins that we provide and highly recommend using them. Due to the flexible nature of these posts we do not feel that a larger cotter pin will give you any more strength. (A Case in Point here: over the years we have had customers bring us, or talked about, broken fiberglass posts. Usually the break is at a pre-drilled hole that was not in use.)