MATL WOVEN GRAPHITE/EPOXY STEPWEDGE; FOUR ROWS OF FLAT BOTTOM DRILLED HOLES ON EACH OF 6 STEPS: 1ST HOLE OF EACH ROW IS 0.045 IN. DEEP; 2ND HOLE OFEACH ROW IS 0.035 IN. DEEP; 3RD HOLE OF EACH ROW IS 0.020 IN. DEEP; 4TH HOLEOF EACH ROW IS 0.005 IN DEEP; ALL HOLES 0.50 IN. DIA; ULTRASONIC