Hello matt33,   These are the screws for the R540 chassis. I think most likely the ones, in Bold, are what you are looking for: 94682  , R9445  , WD06K   Part Number Part Description Def Component Functional Description 4MP69 SCR,M2X4.5,KSH,MS,NI Screw, M2X4.5 Screw, Boss S1 for Version 2 and Version 3 94682  silver SCR,M3X.5X5MM,HEX,PHH,TF,ZPS Screw M3X.5X5MM Screw, Hex Head Phillips Drive, M3X.5X5MM, Zinc Plated Steel, Thread Forming H5VPP SCR,BOSS,V4,V5,M.2 Screw, BOSS S1 Screw, Boss S1 for Version 4 and Version 5 M.2 HFX4T  black SCR,M3X3.5MM,FLH,MSCR,ZPS,T6 Screw, M3X3.5 Screw, Flat Head Machine, M3X3.5MM, Zinc Plated Steel R9445  silver SCR,M3X.05X4.5MM,FLH,MSCR,ZPS Screw, M3X.05X4.5 Screw, Flat Head Machine, M3X.05X4.5MM, Zinc Plated Steel WD06K  black SCR,6-32X.225,PHH,FLH,BLK Screw, 6-32X0.225 Screw, Phillips Drive Flat Head, 6-32X.225, (Black, with NYLOK PATCH replacing G937K Y2R90  silver SCR,6-32X.163,FLH,T8 Screw, 6.32X.163 Screw, Flat Head, 6-32X, 163, Polaris/Sirus Carrier, Torx 8  
What size are the silver and black chassis screws on the outside of the 540? I'm missing a few on a new to me build. Thanks.
R540 chassis screw size