The Bolt,close Tolerance, cataloged under National Stock Number 5306-01-599-4544, is classified within Federal Supply Class 5306 (Bolts) of the Hardware and Abrasives group. The manufacturer of record is The Boeing Company Div Defense. Government technical data includes 20 specifications, cited from the U.S. Government catalog. The record lists 15 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog.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 | 5306-01-599-4544 |
| Primary Part Number | 3M1277E4D21A |
| Item Name | Bolt,close Tolerance |
| FSC / FSG | 5306 / 53 — Bolts |
| Manufacturer | The Boeing Company Div Defense |
| Status | ACTIVE |
| Fastener Length | 1.737 INCHES NOMINAL IN |
| Surface Treatment Document and Classification | MIL-L-87132, TYPE 1, GRADE B MIL SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Thread Length | 0.425 INCHES NOMINAL IN |
| Hole Configuration Style | ROUND |
| Material Document and Classification | AMS5662 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| Nominal Thread Diameter | 0.250 INCHES IN |
| Head Style | FLAT COUNTERSUNK |
| Thread Direction | RIGHT-HAND |
| Grip Length | 1.312 INCHES NOMINAL IN |
| Grip Diameter | 0.2648 INCHES MINIMUM AND 0.2651 INCHES MAXIMUM IN |
| Surface Treatment | PASSIVATE OVERALL |
| Countersink Angle | 90.0 DEGREES MINIMUM AND 101.0 DEGREES MAXIMUM |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 28 |
| Material | NICKEL ALLOY 718 OVERALL |
| Hole Quantity | 1 |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Hole Type | DRILLED |
| Hole Diameter | 0.076 INCHES NOMINAL IN |
| Head Diameter | 0.3859 INCHES MINIMUM AND 0.3948 INCHES MAXIMUM 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 |
|---|---|
| 3M1277E4D21A PRIMARY | The Boeing Company Div Defense (USA) |
| 3M1277E4D21A | Saturn Fasteners Inc (USA) |
| TX1027E4D21A | Sps Technologies Llc Dba PB Fasteners Div PB Fasteners (USA) |
| 3M1277E4D21A | B & B Specialties Inc Dba Gs Aerospace Div Gs Aerospace (USA) |
| 3M1277E4D21A | Valley-Todeco, Inc. Dba Arconic Fastening Systems (USA) |
| 3M1277E4D21A | Houston Precision Fasteners I Lp (USA) |
| 3M1277E4D21A | Fastener Innovation Technology, Inc. Dba F I T (USA) |
| TX1027E4D21A | Hi-Shear Corporation (USA) |
| 3M1277E4D21A | Heartland Precision Fasteners Inc (USA) |
| 3M1277E4D21A | Camcar Llc Div Camcar Llc (USA) |
| WC1277E4D21A | West Coast Aerospace, Inc. (USA) |
| TX1027E4D21A | Sps Technologies, Llc Dba PB Fasteners (USA) |
| 11861E4D21A | Reid Products Inc. Dba Reid Products Inc (USA) |
| TX1027E4D21A | Howmet Global Fastening Systems Inc (USA) |
| TX1027E4D21A | Sps Technologies, Llc Dba Air Industries Company Div Air Industries Company (USA) |
| Reference | Meaning |
|---|---|
| TX1027E4D21A | 5/2 Secondary reference U.S. Government activity |
NSN 5306-01-599-4544 is a Bolt,close Tolerance, manufactured by The Boeing Company Div Defense, classified under FSC 5306, Bolts. Status: active.
NSN 5306-01-599-4544 has 15 manufacturer part numbers on file: 3M1277E4D21A (The Boeing Company Div Defense), 3M1277E4D21A (Saturn Fasteners Inc), TX1027E4D21A (Sps Technologies Llc Dba PB Fasteners Div PB Fasteners), 3M1277E4D21A (B & B Specialties Inc Dba Gs Aerospace Div Gs Aerospace), 3M1277E4D21A (Valley-Todeco, Inc. Dba Arconic Fastening Systems) and 10 more.
Key specifications for 3M1277E4D21A: Fastener Length: 1.737 INCHES NOMINAL IN; Surface Treatment Document and Classification: MIL-L-87132, TYPE 1, GRADE B MIL SPEC SINGLE TREATMENT RESPONSE OVERALL; Thread Length: 0.425 INCHES NOMINAL IN; Hole Configuration Style: ROUND. 20 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.