The 639661-4 is a the manufacturer industrial component. Key specifications include color: BLACK, LUSTERLESS, skirt_style: STEPPED, skirt_design: NONDETACHABLE, overall_depth: 0.740 INCHES MINIMUM IN, inside_diameter: 0.252 INCHES MINIMUM AND 0.254 INCHES MAXIMUM IN, outside_diameter: 1.740 INCHES MINIMUM AND 1.780 INCHES MAXIMUM IN. This part is cataloged in the Federal Logistics Information System (FLIS) under NSN 5355-00-579-6389, indicating validated use in U.S.
government and defense logistics supply chains. Available through authorized enterprise resellers and TPM (Third Party Maintenance) channels. Verify compatibility with your specific system configuration before ordering.
| color | BLACK, LUSTERLESS |
| skirt_style | STEPPED |
| skirt_design | NONDETACHABLE |
| overall_depth | 0.740 INCHES MINIMUM IN |
| inside_diameter | 0.252 INCHES MINIMUM AND 0.254 INCHES MAXIMUM IN |
| outside_diameter | 1.740 INCHES MINIMUM AND 1.780 INCHES MAXIMUM IN |
| screw_drive_type | HEXAGON SOCKET |
| style_designator | ROUND |
| attachment_method | SETSCREWS |
| counterbore_depth | 0.320 INCHES MINIMUM IN |
| overall_thickness | 1.040 INCHES MINIMUM AND 1.100 INCHES MAXIMUM IN |
| nominal_thread_size | 0.164 INCHES SCREW HOLE IN |
| NSN | 5355-00-579-6389 |
| SETSCREW HOLE QUANTITY | 2 |
| COUNTERBORE DIAMETER | 0.750 INCHES MINIMUM IN |
| OVERALL THICKNESS | 1.040 INCHES MINIMUM AND 1.100 INCHES MAXIMUM IN |
| ATTACHMENT METHOD | SETSCREWS |
| SCREW DRIVE TYPE | HEXAGON SOCKET |
| MATERIAL TRANSPARENCY | OPAQUE |
| THREAD SERIES DESIGNATOR | UNIFIED NATIONAL COARSE (UNC) SCREW HOLE |
| SKIRT OUTSIDE DIAMETER | 1.690 INCHES MAXIMUM IN |
| COLOR | BLACK, LUSTERLESS |
| THREAD QUANTITY PER INCH | 32 SCREW HOLE |