The Bolt,close Tolerance, cataloged under National Stock Number 5306-00-208-8561, 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15 specifications, cited from the U.S. Government catalog. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog.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 | 5306-00-208-8561 |
| Item Name | Bolt,close Tolerance |
| FSC / FSG | 5306 / 53 — Bolts |
| Status | ACTIVE |
| Head Height | 2.000 INCHES NOMINAL IN |
| Fastener Length | 6.500 INCHES NOMINAL IN |
| Thread Length | 2.344 INCHES MAXIMUM IN |
| Hardness Rating | 26.0 ROCKWELL C MINIMUM AND 32.0 ROCKWELL C MAXIMUM OVERALL |
| Material Document and Classification | MIL-S-6758 MIL SPEC SINGLE MATERIAL RESPONSE OVERALL |
| Nominal Thread Diameter | 2.500 INCHES IN |
| Head Style | HEXAGON |
| Thread Direction | RIGHT-HAND |
| Grip Length | 4.031 INCHES NOMINAL IN |
| Width Between Flats | 3.645 INCHES MINIMUM AND 3.750 INCHES MAXIMUM IN |
| Grip Diameter | 2.4960 INCHES MINIMUM AND 2.4970 INCHES MAXIMUM IN |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 8 |
| Material | STEEL COMP 4130 OVERALL |
| Thread Series Designator | UN |
| 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 |
|---|---|
| C89573-2 | 3/2 Design control — primary reference U.S. Government activity |
NSN 5306-00-208-8561 is a Bolt,close Tolerance, classified under FSC 5306, Bolts. Status: active.
Key specifications for 5306-00-208-8561: Head Height: 2.000 INCHES NOMINAL IN; Fastener Length: 6.500 INCHES NOMINAL IN; Thread Length: 2.344 INCHES MAXIMUM IN; Hardness Rating: 26.0 ROCKWELL C MINIMUM AND 32.0 ROCKWELL C MAXIMUM OVERALL. 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.