The Bolt,close Tolerance, cataloged under National Stock Number 5306-00-243-2263, 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 18 specifications, cited from the U.S. Government catalog. The record lists 3 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog.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 | 5306-00-243-2263 |
| Primary Part Number | 3M33-4-20A |
| Item Name | Bolt,close Tolerance |
| FSC / FSG | 5306 / 53 — Bolts |
| Manufacturer | The Boeing Company Div Defense |
| Status | ACTIVE |
| Head Height | 0.156 INCHES NOMINAL IN |
| Fastener Length | 1.703 INCHES MINIMUM AND 1.750 INCHES MAXIMUM IN |
| Thread Length | 0.469 INCHES MAXIMUM IN |
| Hole Configuration Style | HEXAGON FLATS |
| Material Document and Classification | AMS 5732 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| Nominal Thread Diameter | 0.250 INCHES IN |
| Head Style | HEXAGON |
| Thread Direction | RIGHT-HAND |
| Grip Length | 1.250 INCHES NOMINAL IN |
| Width Between Flats | 0.428 INCHES MINIMUM AND 0.440 INCHES MAXIMUM IN |
| Grip Diameter | 0.2487 INCHES MINIMUM AND 0.2492 INCHES MAXIMUM IN |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 28 |
| Material | IRON ALLOY 660 OVERALL |
| Hole Quantity | 1 |
| Thread Series Designator | UNF |
| Hole Type | DRILLED |
| Hole Diameter | 0.048 INCHES NOMINAL 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 |
|---|---|
| 3M33-4-20A | Howmet Global Fastening Systems Inc (USA) |
| 3M33-4-20A | Sps Technologies, Llc Dba Air Industries Company Div Air Industries Company (USA) |
| 3M33-4-20A PRIMARY | The Boeing Company Div Defense (USA) |
| Reference | Meaning |
|---|---|
| 3M33-4-20A | 5/2 Secondary reference U.S. Government activity |
NSN 5306-00-243-2263 is a Bolt,close Tolerance, manufactured by The Boeing Company Div Defense, classified under FSC 5306, Bolts. Status: active.
NSN 5306-00-243-2263 has 3 manufacturer part numbers on file: 3M33-4-20A (Howmet Global Fastening Systems Inc), 3M33-4-20A (Sps Technologies, Llc Dba Air Industries Company Div Air Industries Company), 3M33-4-20A (The Boeing Company Div Defense).
Key specifications for 3M33-4-20A: Head Height: 0.156 INCHES NOMINAL IN; Fastener Length: 1.703 INCHES MINIMUM AND 1.750 INCHES MAXIMUM IN; Thread Length: 0.469 INCHES MAXIMUM IN; Hole Configuration Style: HEXAGON FLATS. 18 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.