Imperial 6213 Six Prong T-nut, 1/4-20, Pkg/25 1/4-20 Six Prong T-Nut Eliminates countersinking and adds strength to wood construction by providing a steel thread in wood or plywood Has six claw-like prongs that penetrate the toe in grip so tightly that you have to drive it out of its hole Measurements A: 3/4, B: 5/16, C: .294/.289, D: 15/64, S (plus .015 or minus .000): .042