I just used bolts, if you add a washer then the bolt can't turn and nylock nuts and washers on top, check my hold down board here. I really like the Rockler Track and hold downs
https://www.cnczone.com/forums/chine...cnc-posts.html
I believe these are the correct T Nuts.
https://www.amazon.com/dp/B00JF7AIEM...v_ov_lig_dp_it