The Screw,close Tolerance, cataloged under National Stock Number 5305-00-283-7455, 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 9 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through both NSN and commercial part number lookups. 7 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 2 items share a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5305-00-283-7455 |
| Primary Part Number | HT271A4-8 |
| 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 | 0.952 INCHES MINIMUM AND 0.999 INCHES MAXIMUM IN |
| Thread Length | 0.442 INCHES MINIMUM AND 0.509 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 | 0.490 INCHES MINIMUM AND 0.510 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 |
|---|---|
| ST3M430V4-8AS | Houston Precision Fasteners I Lp (USA) |
| WC8137-4-8A | West Coast Aerospace, Inc. (USA) |
| HT271A4-8 PRIMARY | Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc (CAN) |
| BM33024V4-8U | Huck International, Inc (USA) |
| HT8137-4-8AS | Howmet Global Fastening Systems Inc (USA) |
| ST3M430V4-8AS | Fastener Innovation Technology, Inc. Dba F I T (USA) |
| 110179-4-8AS | Sps Technologies Ltd, Tj Brooks Division (GBR) |
| ST3M430V4-8AS | Twist Tite Mfg, Inc Dba Twist Tite Manufacturing Inc (USA) |
| HT271A4-8 PRIMARY | Hi-Shear Corporation (USA) |
| Reference | Meaning |
|---|---|
| ST3M4 | 5/9 Secondary reference Sps Technologies Inc |
| BM33024V4-8U | 5/9 Secondary reference U.S. Government activity |
| 110179-4-8AS | 5/9 Secondary reference Sps Technologies, Llc Dba PB Fasteners |
| 110179-4-8AS | 5/9 Secondary reference Sps Technologies Inc |
| 10125107 | 6/9 Informative reference only Nimikkeistokeskus Ncb Finland |
| ST3M430V4-8AS | 7/2 Vendor item drawing reference The Boeing Company Div Defense |
| 110179-4-8AS | 3/2 Design control — primary reference U.S. Government activity |
NSN 5305-00-283-7455 is a Screw,close Tolerance, manufactured by Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc, classified under FSC 5305, Screws. Status: active.
NSN 5305-00-283-7455 has 9 manufacturer part numbers on file: ST3M430V4-8AS (Houston Precision Fasteners I Lp), WC8137-4-8A (West Coast Aerospace, Inc.), HT271A4-8 (Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc), BM33024V4-8U (Huck International, Inc), HT8137-4-8AS (Howmet Global Fastening Systems Inc) and 4 more.
2 possible matches (shared part number, not a government interchangeability claim): 5310-01-080-4852, 5305-01-308-9250. Verify interchangeability with system specifications before substitution.
Key specifications for HT271A4-8: 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: 0.952 INCHES MINIMUM AND 0.999 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.