Bolts used to combine two blocks keep the 1/4"-20 SHCP while the Stud Pins start with a 5/8"-11 thread and flare out to fit snugly into a 16mm hole.
These blocks have several useful configurations:
FA16 - 16mm Diameter Holes On 2" Grid Spacing
The FA16 line is a hybrid metric/imperial system that combines 2" hole spacing and 16mm metric sized holes along with Fireball Tools lineup of products.
If your table has 16mm hole diameter with 50mm hole spacing and you want to purchase fixtures, please email us.