What was found
MAIN CABIN FLOOR BEAM UPPER SURFACE IS CORRODED AT FASTENER HOLE BS 1681, LBL 24-BL 47. REMOVED SURFACE CORROSION AS REQUIRED, IAW B757 SRM 53-60-51-1A. ORIGINAL MATERIAL THICKNESS .071. MATERIAL LOSS .006. REMAINING MATERIAL THICKNESS .065 FOUND TO BE WITHIN LIMITS, IAW B757 SRM 53-60-51-1A TABLE 102. REPLACED NUTPLATE STRAP AS REQUIRED, IAW BOEING DRAWING 146N5693 REV "B" AND BOEING DRAWING 146N5300 REV "F" AND B757 SRM 51-40-02.