The Bolt,close Tolerance, cataloged under National Stock Number 5306-00-307-4178, is classified within Federal Supply Class 5306 (Bolts) of the Hardware and Abrasives group. The manufacturer of record is Sikorsky Aircraft Corporation Dba Sikorsky Aircraft Corp. Government technical data includes 22 specifications, cited from the U.S. Government catalog. The record lists 1 manufacturer part number for this item, enabling identification through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5306-00-307-4178 |
| Primary Part Number | SS27576-6-122 |
| Item Name | Bolt,close Tolerance |
| FSC / FSG | 5306 / 53 — Bolts |
| Manufacturer | Sikorsky Aircraft Corporation Dba Sikorsky Aircraft Corp |
| Status | ACTIVE |
| Surface Finish | 63.0 MICROINCHES GRIP |
| Surface Finish | 63.0 MICROINCHES BEARING SURFACE OF HEAD |
| Head Height | 0.189 INCHES MINIMUM AND 0.204 INCHES MAXIMUM IN |
| Fastener Length | 8.164 INCHES MINIMUM AND 8.184 INCHES MAXIMUM IN |
| Surface Treatment Document and Classification | QQ-P-416 TY 2 CLASS 2 FED SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Thread Length | 0.357 INCHES MINIMUM AND 0.439 INCHES MAXIMUM IN |
| Hardness Rating | 36.0 ROCKWELL C MINIMUM AND 41.0 ROCKWELL C MAXIMUM OVERALL |
| Shank Unthreaded Hole Diameter | 0.106 INCHES MINIMUM AND 0.116 INCHES MAXIMUM FIRST HOLE IN |
| Nominal Thread Diameter | 0.375 INCHES IN |
| Head Style | DISHED HEXAGON |
| Thread Direction | RIGHT-HAND |
| Grip Length | 7.625 INCHES MINIMUM AND 7.641 INCHES MAXIMUM IN |
| Width Between Flats | 0.553 INCHES MINIMUM AND 0.564 INCHES MAXIMUM IN |
| Grip Diameter | 0.3733 INCHES MINIMUM AND 0.3742 INCHES MAXIMUM IN |
| Locking Feature | DETENT RING GRIP |
| Surface Treatment | CADMIUM AND CHROMATE OVERALL |
| Minimum Tensile Strength | 95000 POUNDS PER SQUARE INCH LBS |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 24 |
| Material | STEEL COMP E4340 OR STEEL COMP 4140 OR STEEL COMP 8740 OR STEEL COMP 4130 OR STEEL COMP 6150 OVERALL |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Distance From Head Largest Bearing Surface to Shank Hole Center | 8.049 INCHES MINIMUM AND 8.079 INCHES MAXIMUM FIRST HOLE IN |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
| Part Number | Manufacturer |
|---|---|
| SS27576-6-122 | Sikorsky Aircraft Corporation Dba Sikorsky Aircraft Corp (USA) |
| Reference | Meaning |
|---|---|
| MS27576-6-122 | 3/2 Design control — primary reference U.S. Government activity |
| MS27576-6-122 | 5/9 Secondary reference U.S. Government activity |
NSN 5306-00-307-4178 is a Bolt,close Tolerance, manufactured by Sikorsky Aircraft Corporation Dba Sikorsky Aircraft Corp, classified under FSC 5306, Bolts. Status: active.
NSN 5306-00-307-4178 has 1 manufacturer part number on file: SS27576-6-122 (Sikorsky Aircraft Corporation Dba Sikorsky Aircraft Corp).
Key specifications for SS27576-6-122: Surface Finish: 63.0 MICROINCHES GRIP; Surface Finish: 63.0 MICROINCHES BEARING SURFACE OF HEAD; Head Height: 0.189 INCHES MINIMUM AND 0.204 INCHES MAXIMUM IN; Fastener Length: 8.164 INCHES MINIMUM AND 8.184 INCHES MAXIMUM IN. 22 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.