The Screw,close Tolerance, cataloged under National Stock Number 5305-01-028-2470, is classified within Federal Supply Class 5305 (Screws) of the Hardware and Abrasives group. The manufacturer of record is Huck International, Inc. Government technical data includes 19 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through both NSN and commercial part number lookups. 5 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5305-01-028-2470 |
| Primary Part Number | HT4020-4-6A |
| Item Name | Screw,close Tolerance |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | Huck International, Inc |
| Status | ACTIVE |
| Surface Finish | 32.0 MICROINCHES THREADS |
| Surface Finish | 32.0 MICROINCHES GRIP |
| Head Height | 0.071 INCHES MINIMUM AND 0.073 INCHES MAXIMUM IN |
| Fastener Length | 0.828 INCHES MINIMUM AND 0.875 INCHES MAXIMUM IN |
| Thread Length | 0.443 INCHES MINIMUM AND 0.510 INCHES MAXIMUM IN |
| Material Document and Classification | AMS 5629 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| Nominal Thread Diameter | 0.250 INCHES IN |
| Head Style | FLAT COUNTERSUNK UNDERCUT |
| Thread Direction | RIGHT-HAND |
| Grip Length | 0.365 INCHES MINIMUM AND 0.385 INCHES MAXIMUM IN |
| Grip Diameter | 0.2490 INCHES MINIMUM AND 0.2495 INCHES MAXIMUM IN |
| Surface Treatment | PASSIVATE OVERALL |
| Internal Drive Style | HIGH-TORQUE |
| Countersink Angle | 100.0 DEGREES NOMINAL |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 28 |
| Material | STEEL COMP XM-13 OVERALL |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Head Diameter | 0.502 INCHES MINIMUM AND 0.507 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 |
|---|---|
| HT4020-4-6A | Sps Technologies, Llc Dba PB Fasteners (USA) |
| HT4020-4-6A | Sps Technologies, Llc Dba Air Industries Company Div Air Industries Company (USA) |
| HT4020-4-6A PRIMARY | Huck International, Inc (USA) |
| ST3M652C4-6A | Valley-Todeco, Inc. Dba Arconic Fastening Systems (USA) |
| HT4020-4-6A | Sps Technologies Ltd, Tj Brooks Division (GBR) |
| ST3M652C4-6A | Houston Precision Fasteners I Lp (USA) |
| WC4020-4-6A PRIMARY | West Coast Aerospace, Inc. (USA) |
| HT4020-4-6A PRIMARY | Howmet Global Fastening Systems Inc (USA) |
| ST3M652C4-6A | Twist Tite Mfg, Inc Dba Twist Tite Manufacturing Inc (USA) |
| 11925C4-6A | Reid Products Inc. Dba Reid Products Inc (USA) |
| HT4020-4-6A PRIMARY | Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc (CAN) |
| HT4020-4-6A PRIMARY | Hi-Shear Corporation (USA) |
| ST3M652C4-6A PRIMARY | Fastener Innovation Technology, Inc. Dba F I T (USA) |
| ST3M652C4-6A | Heartland Precision Fasteners Inc (USA) |
| HT4020-4-6A | Sps Technologies Llc Dba PB Fasteners Div PB Fasteners (USA) |
| Reference | Meaning |
|---|---|
| HT4020-4-6A | 3/2 Design control — primary reference U.S. Government activity |
| HT4020-4-6A | 5/9 Secondary reference U.S. Government activity |
| ST3M652C4-6A | 7/2 Vendor item drawing reference The Boeing Company Div Defense |
| HT4020-4-6A | 5/9 Secondary reference U.S. Government activity |
| ST3M652C4-6A | 5/9 Secondary reference U.S. Government activity |
NSN 5305-01-028-2470 is a Screw,close Tolerance, manufactured by Huck International, Inc, classified under FSC 5305, Screws. Status: active.
NSN 5305-01-028-2470 has 15 manufacturer part numbers on file: HT4020-4-6A (Sps Technologies, Llc Dba PB Fasteners), HT4020-4-6A (Sps Technologies, Llc Dba Air Industries Company Div Air Industries Company), HT4020-4-6A (Huck International, Inc), ST3M652C4-6A (Valley-Todeco, Inc. Dba Arconic Fastening Systems), HT4020-4-6A (Sps Technologies Ltd, Tj Brooks Division) and 10 more.
Key specifications for HT4020-4-6A: Surface Finish: 32.0 MICROINCHES THREADS; Surface Finish: 32.0 MICROINCHES GRIP; Head Height: 0.071 INCHES MINIMUM AND 0.073 INCHES MAXIMUM IN; Fastener Length: 0.828 INCHES MINIMUM AND 0.875 INCHES MAXIMUM IN. 19 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.