Unlike our SOB standoffs which have a blind thread the SOT series standoffs have a thread which runs all the way through the barrel of the standoff. This allows the standoff to be mounted from either side of the base. These parts are manufactured in 316 stainless steel making them suitable for deck applications. The standoff is inertial (friction) welded to the base yielding a very strong part. The bases are all 1.25" in diameter and we have a variety of thread sizes available. Uses for through deck mounting of hardware or anywhere you need a fixed female thread.