The Screw,close Tolerance, cataloged under National Stock Number 5305-01-478-2840, is classified within Federal Supply Class 5305 (Screws) 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 12 manufacturer part numbers 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog.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 | 5305-01-478-2840 |
| Primary Part Number | 3M1170-V4-21A |
| Item Name | Screw,close Tolerance |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | The Boeing Company Div Defense |
| Status | ACTIVE |
| Head Height | 0.060 INCHES MAXIMUM IN |
| Fastener Length | 1.727 INCHES MINIMUM AND 1.747 INCHES MAXIMUM IN |
| Thread Length | 0.415 INCHES MINIMUM AND 0.435 INCHES MAXIMUM IN |
| Material Document and Classification | NAS4004 NATIONAL SPEC SINGLE MATERIAL RESPONSE OVERALL |
| Spline Major Diameter | 0.219 INCHES MINIMUM AND 0.222 INCHES MAXIMUM IN |
| Nominal Thread Diameter | 0.250 INCHES IN |
| Head Style | FLAT COUNTERSUNK |
| Thread Direction | RIGHT-HAND |
| Grip Length | 0.240 INCHES MINIMUM AND 0.260 INCHES MAXIMUM IN |
| Grip Diameter | 0.2490 INCHES MINIMUM AND 0.2495 INCHES MAXIMUM IN |
| Minimum Tensile Strength | 4230 POUNDS PER SQUARE INCH LBS |
| Internal Drive Style | TORX |
| Countersink Angle | 99.0 DEGREES MINIMUM AND 101.0 DEGREES MAXIMUM |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 28 |
| Material | TITANIUM ALLOY UNS R56400 OVERALL |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Head Diameter | 0.385 INCHES MINIMUM AND 0.394 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 |
|---|---|
| TX1027V4-21A | Howmet Global Fastening Systems Inc (USA) |
| TX1027V4-21A | Hi-Shear Corporation (USA) |
| 3M1170-V4-21A PRIMARY | The Boeing Company Div Defense (USA) |
| TX1027V4-21A | Heartland Precision Fasteners Inc (USA) |
| 3M1170V4-21A | Twist Tite Mfg, Inc Dba Twist Tite Manufacturing Inc (USA) |
| TX1027V4-21A | Fairchild Fasteners Europe - Vsd Gmbh (DEU) |
| TX1027V4-21A | Sps Technologies, Llc Dba Air Industries Company Div Air Industries Company (USA) |
| TX1027V4-21A | Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc (CAN) |
| 11825-V4-21A | Reid Products Inc. Dba Reid Products Inc (USA) |
| 11845-V4-21A | Reid Products Inc. Dba Reid Products Inc (USA) |
| TX1027V4-21A | Sps Technologies, Llc Dba PB Fasteners (USA) |
| TX1027V4-21A | Sps Technologies Llc Dba PB Fasteners Div PB Fasteners (USA) |
| Reference | Meaning |
|---|---|
| TX1027V4-21A | 5/2 Secondary reference U.S. Government activity |
| TX1027V4-21A | 5/9 Secondary reference Sps Technologies Inc |
NSN 5305-01-478-2840 is a Screw,close Tolerance, manufactured by The Boeing Company Div Defense, classified under FSC 5305, Screws. Status: active.
NSN 5305-01-478-2840 has 12 manufacturer part numbers on file: TX1027V4-21A (Howmet Global Fastening Systems Inc), TX1027V4-21A (Hi-Shear Corporation), 3M1170-V4-21A (The Boeing Company Div Defense), TX1027V4-21A (Heartland Precision Fasteners Inc), 3M1170V4-21A (Twist Tite Mfg, Inc Dba Twist Tite Manufacturing Inc) and 7 more.
Key specifications for 3M1170-V4-21A: Head Height: 0.060 INCHES MAXIMUM IN; Fastener Length: 1.727 INCHES MINIMUM AND 1.747 INCHES MAXIMUM IN; Thread Length: 0.415 INCHES MINIMUM AND 0.435 INCHES MAXIMUM IN; Material Document and Classification: NAS4004 NATIONAL SPEC SINGLE MATERIAL RESPONSE OVERALL. 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.