The Screw,close Tolerance, cataloged under National Stock Number 5305-00-285-9229, is classified within Federal Supply Class 5305 (Screws) of the Hardware and Abrasives group. The manufacturer of record is Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc. Government technical data includes 18 specifications, cited from the U.S. Government catalog. The record lists 5 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 7 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5305-00-285-9229 |
| Primary Part Number | HT271A4-9 |
| Item Name | Screw,close Tolerance |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | Lisi Aerospace Canada Corp Div Hi Shear Holdings 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 | 1.015 INCHES MINIMUM AND 1.062 INCHES MAXIMUM IN |
| Thread Length | 0.443 INCHES MINIMUM AND 0.510 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 | 0.250 INCHES IN |
| Head Style | FLAT COUNTERSUNK UNDERCUT |
| Thread Direction | RIGHT-HAND |
| Grip Length | 0.552 INCHES MINIMUM AND 0.572 INCHES MAXIMUM IN |
| Grip Diameter | 0.2490 INCHES MINIMUM AND 0.2495 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 | 28 |
| Material | TITANIUM ALLOY 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 |
|---|---|
| 110179-4-9AS | Sps Technologies Ltd, Tj Brooks Division (GBR) |
| HT271A4-9 PRIMARY | Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc (CAN) |
| HT271A4-9 PRIMARY | Hi-Shear Corporation (USA) |
| ST3M430V4-9AS | Twist Tite Mfg, Inc Dba Twist Tite Manufacturing Inc (USA) |
| ST3M430V4-9AS | The Boeing Company Div Defense (USA) |
| Reference | Meaning |
|---|---|
| WC8137-4-9A | C/1 Advisory reference — outside the item-of-supply concept West Coast Aerospace, Inc. |
| HT8137-4-9AS | 5/9 Secondary reference U.S. Government activity |
| 10125110 | 6/9 Informative reference only Nimikkeistokeskus Ncb Finland |
| 110179-4-9AS | 3/2 Design control — primary reference U.S. Government activity |
| ST3M430V4-9AS | C/1 Advisory reference — outside the item-of-supply concept Fastener Innovation Technology, Inc. Dba F I T |
| BM33024V4-9U | 5/9 Secondary reference U.S. Government activity |
| 110179-4-9AS | 5/9 Secondary reference Sps Technologies, Llc Dba PB Fasteners |
NSN 5305-00-285-9229 is a Screw,close Tolerance, manufactured by Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc, classified under FSC 5305, Screws. Status: active.
NSN 5305-00-285-9229 has 5 manufacturer part numbers on file: 110179-4-9AS (Sps Technologies Ltd, Tj Brooks Division), HT271A4-9 (Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc), HT271A4-9 (Hi-Shear Corporation), ST3M430V4-9AS (Twist Tite Mfg, Inc Dba Twist Tite Manufacturing Inc), ST3M430V4-9AS (The Boeing Company Div Defense).
Key specifications for HT271A4-9: 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: 1.015 INCHES MINIMUM AND 1.062 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.