The Screw,close Tolerance, cataloged under National Stock Number 5305-01-145-9178, is classified within Federal Supply Class 5305 (Screws) of the Hardware and Abrasives group. The manufacturer of record is Northrop Grumman Systems Corporation. Government technical data includes 18 specifications, cited from the U.S. Government catalog. The record lists 4 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog.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 | 5305-01-145-9178 |
| Primary Part Number | GB510DF8-19 |
| Item Name | Screw,close Tolerance |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | Northrop Grumman Systems Corporation |
| Status | ACTIVE |
| Width Across Flats | 0.190 INCHES MINIMUM AND 0.193 INCHES MAXIMUM IN |
| Fastener Length | 1.753 INCHES MINIMUM AND 1.773 INCHES MAXIMUM IN |
| Surface Treatment Document and Classification | QQ-P-416,TY 2,CL 2 FED SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Thread Length | 0.560 INCHES MINIMUM AND 0.590 INCHES MAXIMUM IN |
| Material Document and Classification | AMS5628 ASSN STD SINGLE MATERIAL RESPONSE OR MIL-S-18732 MIL SPEC SINGLE MATERIAL RESPONSE OVERALL |
| Nominal Thread Diameter | 0.438 INCHES IN |
| Head Style | FLAT COUNTERSUNK |
| Thread Direction | RIGHT-HAND |
| Grip Length | 1.183 INCHES MINIMUM AND 1.193 INCHES MAXIMUM IN |
| Grip Diameter | 0.4985 INCHES MINIMUM AND 0.4995 INCHES MAXIMUM IN |
| Surface Treatment | CADMIUM AND CHROMATE OVERALL |
| Internal Drive Style | HEXAGON |
| Countersink Angle | 100.0 DEGREES NOMINAL |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 20 |
| Material | STEEL COMP 431 OVERALL |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Head Diameter | 0.748 INCHES MINIMUM AND 0.754 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 |
|---|---|
| GB510DF8-19 | Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc (CAN) |
| GB510DF8-19 | Hi-Shear Corporation (USA) |
| HL403-16-19# | Sps Technologies, Llc Dba PB Fasteners (USA) |
| GB510DF8-19 PRIMARY | Northrop Grumman Systems Corporation (USA) |
| Reference | Meaning |
|---|---|
| GB510DF8-19 | 5/2 Secondary reference U.S. Government activity |
| GB510DF8-19 | 5/9 Secondary reference Holman Mfg Co Inc |
NSN 5305-01-145-9178 is a Screw,close Tolerance, manufactured by Northrop Grumman Systems Corporation, classified under FSC 5305, Screws. Status: active.
NSN 5305-01-145-9178 has 4 manufacturer part numbers on file: GB510DF8-19 (Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc), GB510DF8-19 (Hi-Shear Corporation), HL403-16-19# (Sps Technologies, Llc Dba PB Fasteners), GB510DF8-19 (Northrop Grumman Systems Corporation).
Key specifications for GB510DF8-19: Width Across Flats: 0.190 INCHES MINIMUM AND 0.193 INCHES MAXIMUM IN; Fastener Length: 1.753 INCHES MINIMUM AND 1.773 INCHES MAXIMUM IN; Surface Treatment Document and Classification: QQ-P-416,TY 2,CL 2 FED SPEC SINGLE TREATMENT RESPONSE OVERALL; Thread Length: 0.560 INCHES MINIMUM AND 0.590 INCHES MAXIMUM IN. 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.