NAS609 Socket Head Cap Screw (Non-Preferred treaded) Inactive for Design, see NAS1351 and 1352. Socket Cap Screws come in different types and sizes including: MS21295, MS16995, MS16996, MS16997, MS16998, MS24667, MS24671, MS24672, MS24673, MS24674, MS24677, MS24678, MS51975, NAS608, NAS609. NAS609 SCREWS – SOCKET HEAD CAP (NON-PREFERRED TREADED) INACTIVE FOR DESIGN SEE NAS1351 AND 1352