I created a block, change units to mmNs, Insert-Hole, Selected clearance hole UNC for a 1/2-13 bolt and it created a 33/64 (13.10) hole in my block.
2001 build 2003161.
Wildfire build 2003170
"Wildfires are dangerous, hard to control, and economically catastrophic."
Ben Loosli
CAD/CAM System Analyst
Ingersoll-Rand