The Bolt,close Tolerance, cataloged under National Stock Number 5306-00-003-4109, 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 21 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through both NSN and commercial part number lookups. 5 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5306-00-003-4109 |
| Primary Part Number | SS27576-5-28 |
| 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 | 0.157 INCHES MINIMUM AND 0.157 INCHES MINIMUM AND 0.172 INCHES MAXIMUM0.172 INCHES MAXIMUM IN |
| Fastener Length | 2.228 INCHES MINIMUM AND 2.228 INCHES MINIMUM AND 2.248 INCHES MAXIMUM2.248 INCHES MAXIMUM IN |
| Surface Treatment Document and Classification | QQ-P-416 TY 2 CL 2 FED SPEC ALL TREATMENT RESPONSES OVERALL |
| Thread Length | 0.311 INCHES MINIMUM AND 0.311 INCHES MINIMUM AND 0.378 INCHES MAXIMUM0.378 INCHES MAXIMUM IN |
| Hardness Rating | 36.0 ROCKWELL C MINIMUM AND 41.0 ROCKWELL C MAXIMUM OVERALL |
| Shank Unthreaded Hole Diameter | 0.076 INCHES MINIMUM AND 0.086 INCHES MAXIMUM FIRST HOLE IN |
| Material Document and Classification | MIL-B-83050 MIL SPEC SINGLE MATERIAL RESPONSE OVERALL |
| Nominal Thread Diameter | 0.312 INCHES IN |
| Head Style | DISHED HEXAGONDISHED HEXAGON |
| Thread Direction | RIGHT-HANDRIGHT-HAND |
| Grip Length | 1.750 INCHES MINIMUM AND 1.766 INCHES MAXIMUM IN |
| Width Between Flats | 0.492 INCHES MINIMUM AND 0.492 INCHES MINIMUM AND 0.502 INCHES MAXIMUM0.502 INCHES MAXIMUM IN |
| Grip Diameter | 0.3108 INCHES MINIMUM AND 0.3108 INCHES MINIMUM AND 0.3117 INCHES MAXIMUM0.3117 INCHES MAXIMUM IN |
| Surface Treatment | CADMIUM AND CHROMATE OVERALL |
| Thread Class | 3A3A |
| Thread Quantity Per Inch | 24 |
| Material | STEEL OVERALL |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Distance From Head Largest Bearing Surface to Shank Hole Center | 2.113 INCHES MINIMUM AND 2.143 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 |
|---|---|
| SS27576-5-28 | Sikorsky Aircraft Corporation Dba Sikorsky Aircraft Corp (USA) |
| Reference | Meaning |
|---|---|
| 106467-5-28 | 5/2 Secondary reference U.S. Government activity |
| AC194-5-28 | 5/2 Secondary reference U.S. Government activity |
| MS27576-5-28 | 5/9 Secondary reference U.S. Government activity |
| CA4510-5-28 | 5/9 Secondary reference Howmet Global Fastening Systems Inc. Div Tridair Products |
| MS27576-5-28 | 3/2 Design control — primary reference U.S. Government activity |
NSN 5306-00-003-4109 is a Bolt,close Tolerance, manufactured by Sikorsky Aircraft Corporation Dba Sikorsky Aircraft Corp, classified under FSC 5306, Bolts. Status: active.
NSN 5306-00-003-4109 has 1 manufacturer part number on file: SS27576-5-28 (Sikorsky Aircraft Corporation Dba Sikorsky Aircraft Corp).
Key specifications for SS27576-5-28: Surface Finish: 63.0 MICROINCHES GRIP; Surface Finish: 63.0 MICROINCHES BEARING SURFACE OF HEAD; Head Height: 0.157 INCHES MINIMUM AND 0.157 INCHES MINIMUM AND 0.172 INCHES MAXIMUM0.172 INCHES MAXIMUM IN; Fastener Length: 2.228 INCHES MINIMUM AND 2.228 INCHES MINIMUM AND 2.248 INCHES MAXIMUM2.248 INCHES MAXIMUM IN. 21 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.