The DSXF2 with the THK option provides for a Knuckle with 1/2” NPS threaded pipe. A suitable recommendation for a stanchion mount would be the KFLSTMTHK option which accepts a 1/2" NPT knuckle. Both the NPT and NPS have the same thread angle, shape, and pitch (threads per inch). However, NPT threads are tapered and NPS threads are straight (parallel). Both threads have a 60° included angle and have flat peaks and valleys and are compatible with each other.
The DSXF2 with the THK option provides a male 1/2" threaded that is suitable for mating with the female threading on the KFLSTMTHK stanchion mount. Aside, the AFSTMTHK is not compatible with the THK option on the DSXF2 as that AFSTMTHK mount is suitable for a 3/4" NPS THK.