The Bolt,close Tolerance, cataloged under National Stock Number 5306-00-678-9661, is classified within Federal Supply Class 5306 (Bolts) of the Hardware and Abrasives group. Government technical data includes 15 specifications, cited from the U.S. Government catalog. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5306-00-678-9661 |
| Item Name | Bolt,close Tolerance |
| FSC / FSG | 5306 / 53 — Bolts |
| Status | ACTIVE |
| Surface Finish | 32.0 MICROINCHES GRIP |
| Head Height | 0.204 INCHES MINIMUM AND 0.234 INCHES MAXIMUM IN |
| Fastener Length | 0.953 INCHES MINIMUM AND 0.983 INCHES MAXIMUM IN |
| Thread Length | 0.760 INCHES MINIMUM AND 0.800 INCHES MAXIMUM IN |
| Hardness Rating | 45.0 ROCKWELL C NOMINAL OVERALL |
| Nominal Thread Diameter | 0.375 INCHES IN |
| Head Style | HEXAGON |
| Thread Direction | RIGHT-HAND |
| Grip Length | 0.183 INCHES MINIMUM AND 0.193 INCHES MAXIMUM IN |
| Width Between Flats | 0.620 INCHES MINIMUM AND 0.630 INCHES MAXIMUM IN |
| Grip Diameter | 0.4995 INCHES MINIMUM AND 0.5000 INCHES MAXIMUM IN |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 24 |
| Material | STEEL COMP 4140 OR STEEL COMP 8740 OR STEEL COMP E4340 OR STEEL COMP 4340 OVERALL |
| Thread Series Designator | UNF |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
| Reference | Meaning |
|---|---|
| 693077 | 3/2 Design control — primary reference U.S. Government activity |
NSN 5306-00-678-9661 is a Bolt,close Tolerance, classified under FSC 5306, Bolts. Status: active.
Key specifications for 5306-00-678-9661: Surface Finish: 32.0 MICROINCHES GRIP; Head Height: 0.204 INCHES MINIMUM AND 0.234 INCHES MAXIMUM IN; Fastener Length: 0.953 INCHES MINIMUM AND 0.983 INCHES MAXIMUM IN; Thread Length: 0.760 INCHES MINIMUM AND 0.800 INCHES MAXIMUM IN. 15 specifications are documented in the U.S. Government catalog.
No hazard code in the DLA record (HMIC N). Hazard information on this page is shown exactly as it appears in the DLA record.
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-16.
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-18.