What was found
MAIN CABIN FLOOR BEAM UPPER SURFACE IS CORRODED AT FASTENER HOLE BS 1681, BL 4-RBL 54. REMOVED SURFACE CORROSION AS REQUIRED, IAW B757 SRM 53-60-51-1A. ORIGINAL MATERIAL THICKNESS .071, MATERIAL LOSS .004 REMAINING MATERIAL THICKNESS .067 FOUND TO BE WITHIN LIMITS, IAW B757 SRM 53-60-51-1A TABLE 2. REPLACED NUTPLATE STRAP AS REQUIRED, IAW BOEING DWG 146N5693 REV "B" AND 146N5300 REV "F" AND B757 SRM 51-40-02.