The Screw,close Tolerance, cataloged under National Stock Number 5305-01-526-6960, 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 6 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5305-01-526-6960 |
| Primary Part Number | HT4027-4-18 |
| Item Name | Screw,close Tolerance |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | Howmet Global Fastening Systems Inc |
| Status | ACTIVE |
| Head Height | 0.015 INCHES NOMINAL IN |
| Fastener Length | 1.594 INCHES NOMINAL IN |
| Surface Treatment Document and Classification | QQ-P-35 FED SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Thread Length | 0.469 INCHES NOMINAL IN |
| Material Document and Classification | AMS5662 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| Nominal Thread Diameter | 0.250 INCHES IN |
| Head Style | FILLISTER COUNTERSUNK |
| Thread Direction | RIGHT-HAND |
| Grip Length | 1.125 INCHES NOMINAL IN |
| Grip Diameter | 0.249 INCHES MINIMUM AND 0.250 INCHES MAXIMUM IN |
| Surface Treatment | PASSIVATE OVERALL |
| 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 | NICKEL ALLOY 718 OVERALL |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Head Diameter | 0.390 INCHES MINIMUM AND 0.395 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 |
|---|---|
| ST3M557-4-18 | Fastener Innovation Technology, Inc. Dba F I T (USA) |
| WC4027-4-18 | West Coast Aerospace, Inc. (USA) |
| HT4027-4-18 | Sps Technologies, Llc Dba PB Fasteners (USA) |
| HT4027-4-18 | Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc (CAN) |
| HT4027-4-18 PRIMARY | Howmet Global Fastening Systems Inc (USA) |
| HT4027-4-18 | Hi-Shear Corporation (USA) |
| Reference | Meaning |
|---|---|
| ST3M557-4-18 | 7/2 Vendor item drawing reference The Boeing Company Div Defense |
| HT4027-4-18 | 5/2 Secondary reference U.S. Government activity |
NSN 5305-01-526-6960 is a Screw,close Tolerance, manufactured by Howmet Global Fastening Systems Inc, classified under FSC 5305, Screws. Status: active.
NSN 5305-01-526-6960 has 6 manufacturer part numbers on file: ST3M557-4-18 (Fastener Innovation Technology, Inc. Dba F I T), WC4027-4-18 (West Coast Aerospace, Inc.), HT4027-4-18 (Sps Technologies, Llc Dba PB Fasteners), HT4027-4-18 (Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc), HT4027-4-18 (Howmet Global Fastening Systems Inc) and 1 more.
Key specifications for HT4027-4-18: Head Height: 0.015 INCHES NOMINAL IN; Fastener Length: 1.594 INCHES NOMINAL IN; Surface Treatment Document and Classification: QQ-P-35 FED SPEC SINGLE TREATMENT RESPONSE OVERALL; Thread Length: 0.469 INCHES NOMINAL 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.