The Bolt,close Tolerance, cataloged under National Stock Number 5306-01-448-8309, is classified within Federal Supply Class 5306 (Bolts) of the Hardware and Abrasives group. The manufacturer of record is Mac Fasteners, Inc. Dba Mac Fasteners Inc. Government technical data includes 17 specifications, cited from the U.S. Government catalog. The record lists 5 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5306-01-448-8309 |
| Primary Part Number | NAS6604D21 |
| Item Name | Bolt,close Tolerance |
| FSC / FSG | 5306 / 53 — Bolts |
| Manufacturer | Mac Fasteners, Inc. Dba Mac Fasteners Inc |
| Status | ACTIVE |
| Head Height | 0.125 INCHES MINIMUM AND 0.140 INCHES MAXIMUM IN |
| Fastener Length | 0.970 INCHES MINIMUM AND 1.030 INCHES MAXIMUM IN |
| Surface Treatment Document and Classification | QQ-P-416,TY2,CL2 MIL SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Thread Length | 0.425 INCHES NOMINAL IN |
| Shank Unthreaded Hole Diameter | 0.076 INCHES MINIMUM AND 0.086 INCHES MAXIMUM FIRST HOLE IN |
| Material Document and Classification | MIL-S-5000,4340 MIL SPEC SINGLE MATERIAL RESPONSE OR MIL-S-6049,8740 MIL SPEC SINGLE MATERIAL RESPONSE OR AMS6322 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| Nominal Thread Diameter | 0.250 INCHES IN |
| Head Style | HEXAGON |
| Thread Direction | RIGHT-HAND |
| Grip Length | 1.302 INCHES MINIMUM AND 1.322 INCHES MAXIMUM IN |
| Width Between Flats | 0.429 INCHES MINIMUM AND 0.439 INCHES MAXIMUM IN |
| Grip Diameter | 0.2485 INCHES MINIMUM AND 0.2495 INCHES MAXIMUM IN |
| Surface Treatment | CADMIUM OVERALL |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 28 |
| Material | STEEL OVERALL |
| Distance From Head Largest Bearing Surface to Shank Hole Center | 0.284 INCHES MINIMUM AND 0.334 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 |
|---|---|
| NAS6604D21 | Mac Fasteners, Inc. Dba Mac Fasteners Inc (USA) |
| NAS6604D21 | California Screw Products Corp. (USA) |
| NAS6604D21 | Leonardo Spa Helicopters Division - Production Site (ITA) |
| NAS6604D21 | Heartland Precision Fasteners Inc (USA) |
| NAS6604D21 | Northrop Grumman Systems Corporation (USA) |
| Reference | Meaning |
|---|---|
| NAS6604D21 | 3/2 Design control — primary reference U.S. Government activity |
NSN 5306-01-448-8309 is a Bolt,close Tolerance, manufactured by Mac Fasteners, Inc. Dba Mac Fasteners Inc, classified under FSC 5306, Bolts. Status: active.
NSN 5306-01-448-8309 has 5 manufacturer part numbers on file: NAS6604D21 (Mac Fasteners, Inc. Dba Mac Fasteners Inc), NAS6604D21 (California Screw Products Corp.), NAS6604D21 (Leonardo Spa Helicopters Division - Production Site), NAS6604D21 (Heartland Precision Fasteners Inc), NAS6604D21 (Northrop Grumman Systems Corporation).
Key specifications for NAS6604D21: Head Height: 0.125 INCHES MINIMUM AND 0.140 INCHES MAXIMUM IN; Fastener Length: 0.970 INCHES MINIMUM AND 1.030 INCHES MAXIMUM IN; Surface Treatment Document and Classification: QQ-P-416,TY2,CL2 MIL SPEC SINGLE TREATMENT RESPONSE OVERALL; Thread Length: 0.425 INCHES NOMINAL IN. 17 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.