The Setscrew, cataloged under National Stock Number 5305-00-249-0591, is classified within Federal Supply Class 5305 (No Item Name Available) of the Hardware and Abrasives group. The primary manufacturer of record is Federal Specifications Promulgated by General Services Administration Washington DC. Government technical data includes 14 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 2 commercial cross-references from 2 manufacturers, enabling identification through both NSN and commercial part number lookups. 12 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5305-00-249-0591 |
| Primary Part Number | FF-S-21 |
| Item Name | Setscrew |
| FSC / FSG | 5305 / 53 — No Item Name Available |
| Manufacturer | Federal Specifications Promulgated by General Services Administration Washington DC |
| Status | ACTIVE |
| Thread Series Designator | UNIFIED NATIONAL COARSE (UNC) |
| Hardness Rating | 45.0 ROCKWELL C MINIMUM AND 53.0 ROCKWELL C MAXIMUM OVERALL |
| Nondefinitive Spec/std Data | A TYPE |
| Fastener Length | 1.438 INCHES MINIMUM AND 1.500 INCHES MAXIMUM IN |
| Thread Class | 3A A |
| Width Between Flats | 0.241 INCHES MINIMUM AND 0.250 INCHES MAXIMUM IN |
| Head Style | SQUARE |
| Thread Quantity Per Inch | 20 |
| Point Style | CUP |
| Head Height | 0.178 INCHES MINIMUM AND 0.196 INCHES MAXIMUM IN |
| Thread Direction | RIGHT-HAND |
| Internal Drive Style | W/O INTERNAL DRIVE |
| Nominal Thread Diameter | 0.250 INCHES IN |
| Material Document and Classification | 66 FED STD ALL MATERIAL RESPONSES OVERALL |
| Acquisition Status | ACTIVE |
| HAZMAT | No |
| Part Number | Manufacturer |
|---|---|
| FF-S-21 | Federal Specifications Promulgated by General Services Administration Washington DC (USA) |
| MIL-B-933TYPEA | Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M |
NSN 5305-00-249-0591 is a Setscrew, manufactured by Federal Specifications Promulgated by General Services Administration Washington DC, classified under FSC 5305 (No Item Name Available). Status: active.
NSN 5305-00-249-0591 has 2 cross-referenced part numbers: FF-S-21 (Federal Specifications Promulgated by General Services Administration Washington DC), MIL-B-933TYPEA (Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M).
There are 12 known substitutes for 5305-00-249-0591: 5305-00-190-1447, 5310-00-199-3079, 5310-00-199-6548 and 9 more. Verify interchangeability with system specifications before substitution.
Key specifications for FF-S-21: Thread Series Designator: UNIFIED NATIONAL COARSE (UNC); Hardness Rating: 45.0 ROCKWELL C MINIMUM AND 53.0 ROCKWELL C MAXIMUM OVERALL; Nondefinitive Spec/std Data: A TYPE; Fastener Length: 1.438 INCHES MINIMUM AND 1.500 INCHES MAXIMUM IN. 15 total characteristics are documented in the Federal Logistics Information System.