The Screw,close Tolerance, cataloged under National Stock Number 5305-01-310-9996, 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 21 specifications, cited from the U.S. Government catalog. The record lists 8 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through both NSN and commercial part number lookups. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog.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 | 5305-01-310-9996 |
| Primary Part Number | HT8137-4-6ASM |
| 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 |
| Surface Finish | 32.0 MICROINCHES BEARING SURFACE OF HEAD |
| Head Height | 0.0713 INCHES MINIMUM AND 0.0733 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 4967 ASSN STD SINGLE MATERIAL RESPONSE FASTENER |
| Nominal Thread Diameter | 0.250 INCHES IN |
| Features Provided | DRY FILM LUBRICANT AND O RING AND CETYL ALCOHOL LUBRICANT |
| Head Style | FLAT COUNTERSUNK UNDERCUT |
| Thread Direction | RIGHT-HAND |
| Grip Length | 0.365 INCHES MINIMUM AND 0.385 INCHES MAXIMUM IN |
| Grip Diameter | 0.2485 INCHES MINIMUM AND 0.2495 INCHES MAXIMUM IN |
| Minimum Tensile Strength | 160000 POUNDS PER SQUARE INCH LBS |
| Internal Drive Style | HIGH-TORQUE |
| 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 FASTENER |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Head Diameter | 0.4750 INCHES MINIMUM AND 0.5066 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 |
|---|---|
| ST3M430V4-6ASM | Houston Precision Fasteners I Lp (USA) |
| WC8137-4-6A | West Coast Aerospace, Inc. (USA) |
| 110179-4-6ASM | Sps Technologies Ltd, Tj Brooks Division (GBR) |
| HT8137-4-6ASM PRIMARY | Howmet Global Fastening Systems Inc (USA) |
| ST3M430V4-6ASM | Fastener Innovation Technology, Inc. Dba F I T (USA) |
| BM33024V4-6U | Huck International, Inc (USA) |
| HT271A4-6M | Hi-Shear Corporation (USA) |
| ST3M430V4-6ASM | The Boeing Company Div Defense (USA) |
| Reference | Meaning |
|---|---|
| HT271A4-6M | 5/9 Secondary reference Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc |
| 110179-4-6ASM | 5/2 Secondary reference U.S. Government activity |
| HT8137-4-6ASM | 5/9 Secondary reference U.S. Government activity |
NSN 5305-01-310-9996 is a Screw,close Tolerance, manufactured by Howmet Global Fastening Systems Inc, classified under FSC 5305, Screws. Status: active.
NSN 5305-01-310-9996 has 8 manufacturer part numbers on file: ST3M430V4-6ASM (Houston Precision Fasteners I Lp), WC8137-4-6A (West Coast Aerospace, Inc.), 110179-4-6ASM (Sps Technologies Ltd, Tj Brooks Division), HT8137-4-6ASM (Howmet Global Fastening Systems Inc), ST3M430V4-6ASM (Fastener Innovation Technology, Inc. Dba F I T) and 3 more.
Key specifications for HT8137-4-6ASM: Surface Finish: 32.0 MICROINCHES THREADS; Surface Finish: 32.0 MICROINCHES GRIP; Surface Finish: 32.0 MICROINCHES BEARING SURFACE OF HEAD; Head Height: 0.0713 INCHES MINIMUM AND 0.0733 INCHES MAXIMUM IN. 21 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.