T-nuts are available with 3, 4 or 6 prongs, each with its own advantages. Generally, 3-prong nuts are used for plywood, 4-prong nuts for hard or soft wood and 6-prong nuts for softer materials and composites.
They have 3/4" dia. flanges with a 5/16" barrel height and a 7/32" prong height. A 5/16" pre-drill is recommended.
Sold in bags of 10 or 100.