The Screw,close Tolerance, cataloged under National Stock Number 5305-00-283-4579, is classified within Federal Supply Class 5305 (Screws) of the Hardware and Abrasives group. The manufacturer of record is Howmet Global Fastening Systems Inc. Government technical data includes 18 specifications, cited from the U.S. Government catalog. The record lists 9 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5305-00-283-4579 |
| Primary Part Number | HT8137-3-4AS |
| Item Name | Screw,close Tolerance |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | Howmet Global Fastening Systems Inc |
| Status | ACTIVE |
| Surface Finish | 32.0 MICROINCHES THREADS |
| Surface Finish | 32.0 MICROINCHES GRIP |
| Head Height | 0.044 INCHES MINIMUM IN |
| Fastener Length | 0.640 INCHES MINIMUM AND 0.687 INCHES MAXIMUM IN |
| Thread Length | 0.380 INCHES MINIMUM AND 0.447 INCHES MAXIMUM IN |
| Material Document and Classification | NAS621 COMP 6AL-4V ASSN STD SINGLE MATERIAL RESPONSE OR AMS4928 ASSN STD SINGLE MATERIAL RESPONSE OVERALL V |
| Nominal Thread Diameter | 0.190 INCHES IN |
| Head Style | FLAT COUNTERSUNK UNDERCUT |
| Thread Direction | RIGHT-HAND |
| Grip Length | 0.240 INCHES MINIMUM AND 0.260 INCHES MAXIMUM IN |
| Grip Diameter | 0.1890 INCHES MINIMUM AND 0.1895 INCHES MAXIMUM IN |
| Internal Drive Style | HIGH-TORQUE |
| Countersink Angle | 99.5 DEGREES MINIMUM AND 100.5 DEGREES MAXIMUM |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 32 |
| Material | TITANIUM ALLOY OVERALL |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Head Diameter | 0.376 INCHES MINIMUM AND 0.381 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 |
|---|---|
| HT8137-3-4AS PRIMARY | Howmet Global Fastening Systems Inc (USA) |
| ST3M430V3-4AS | Twist Tite Mfg, Inc Dba Twist Tite Manufacturing Inc (USA) |
| HT271A3-4 PRIMARY | Hi-Shear Corporation (USA) |
| BM33024V3-4U PRIMARY | Huck International, Inc (USA) |
| ST3M430V3-4AS | Fastener Innovation Technology, Inc. Dba F I T (USA) |
| ST3M430V3-4AS | Houston Precision Fasteners I Lp (USA) |
| HT271A3-4 PRIMARY | Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc (CAN) |
| WC8137-3-4A | West Coast Aerospace, Inc. (USA) |
| 110179-3-4AS | Sps Technologies Ltd, Tj Brooks Division (GBR) |
| Reference | Meaning |
|---|---|
| ST3M430V3-4AS | 7/2 Vendor item drawing reference The Boeing Company Div Defense |
| 110179-3-4AS | 3/2 Design control — primary reference U.S. Government activity |
| BM33024V3-4U | 5/9 Secondary reference U.S. Government activity |
NSN 5305-00-283-4579 is a Screw,close Tolerance, manufactured by Howmet Global Fastening Systems Inc, classified under FSC 5305, Screws. Status: active.
NSN 5305-00-283-4579 has 9 manufacturer part numbers on file: HT8137-3-4AS (Howmet Global Fastening Systems Inc), ST3M430V3-4AS (Twist Tite Mfg, Inc Dba Twist Tite Manufacturing Inc), HT271A3-4 (Hi-Shear Corporation), BM33024V3-4U (Huck International, Inc), ST3M430V3-4AS (Fastener Innovation Technology, Inc. Dba F I T) and 4 more.
Key specifications for HT8137-3-4AS: Surface Finish: 32.0 MICROINCHES THREADS; Surface Finish: 32.0 MICROINCHES GRIP; Head Height: 0.044 INCHES MINIMUM IN; Fastener Length: 0.640 INCHES MINIMUM AND 0.687 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.