9aluminum mil-a-19070 5068 temper h32, u shape channel, 0.125 in. Thk, 68.000 in. Lg, 1.375 in. O/a w, 2.000 in. O/a h, 10 holes 0.437 in. Dia, 5 on ea side of stiffener equally spaced on center line along the lg, first hole 4.000 in. From end to hole center