6-32 taps are particularly fragile. I should know, I broke two of them in work myself in the past month. Are you tapping the end of the rod or cross drilling and tapping? If end tapping, I would use a lathe and support the tap wrench with the tail stock center. As said above, use a fresh good quality tap and cutting oil. Lock the headstock and carefully turn the tap wrench, advancing the tailstock as you go. If you have a spring loaded tap guide it makes the job easier. Watch the tap as you work. If you see it twisting, back it off. Clean any chips, relube, and continue. So and steady! If a blind hole be careful as you reach the bottom. Something has to give and it is usually the tap. USE A TAPER TAP! I run the taper tap first and follow with the plug tap and finally the bottoming tap if necessary. If your drill depth is deep enough to provide clearance for the taper tap for the desired thread depth, you can forgo the latter two provided you have enough thread depth. If you are cross drilling and tapping, use a Vee block. center the drill in the bottom of the vee and clamp the block to the table. Place the rod in position and clamp it as well. Drill your tap hole and without removing the rod put a tap guide in the chuck and as as for end tapping.