The Screw,cap,hexagon Head, cataloged under National Stock Number 5305-00-159-3538, is classified within Federal Supply Class 5305 (Screws) of the Hardware and Abrasives group. The manufacturer of record is Twin Disc, Incorporated Dba Twin Disc Mid-Atlantic. Government technical data includes 16 specifications, cited from the U.S. Government catalog. The record lists 1 manufacturer part number for this item, enabling identification through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5305-00-159-3538 |
| Primary Part Number | M2721B |
| Item Name | Screw,cap,hexagon Head |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | Twin Disc, Incorporated Dba Twin Disc Mid-Atlantic |
| Status | ACTIVE |
| Head Height | 0.327 INCHES MAXIMUM IN |
| Fastener Length | 1.750 INCHES NOMINAL IN |
| Thread Length | 1.250 INCHES MINIMUM IN |
| Hardness Rating | 32.0 ROCKWELL C MINIMUM AND 38.0 ROCKWELL C MAXIMUM OVERALL |
| Material Document and Classification | SAE GR 8 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| Nominal Thread Diameter | 0.500 INCHES IN |
| Features Provided | UNFINISHED HEAD |
| Head Style | HEXAGON |
| Thread Direction | RIGHT-HAND |
| Width Between Flats | 0.750 INCHES MAXIMUM IN |
| Locking Feature | DISTORTIONS BEARING SURFACE OF HEAD |
| Minimum Tensile Strength | 150000 POUNDS PER SQUARE INCH LBS |
| Thread Class | 2A A |
| Thread Quantity Per Inch | 13 |
| Material | STEEL OVERALL |
| Thread Series Designator | UNIFIED NATIONAL COARSE (UNC) |
| 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 |
|---|---|
| M2721B PRIMARY | Twin Disc, Incorporated Dba Twin Disc Mid-Atlantic (USA) |
| Reference | Meaning |
|---|---|
| A720050C175 | C/1 Advisory reference — outside the item-of-supply concept Zf Industrieantriebe Witten Gmbh |
NSN 5305-00-159-3538 is a Screw,cap,hexagon Head, manufactured by Twin Disc, Incorporated Dba Twin Disc Mid-Atlantic, classified under FSC 5305, Screws. Status: active.
NSN 5305-00-159-3538 has 1 manufacturer part number on file: M2721B (Twin Disc, Incorporated Dba Twin Disc Mid-Atlantic).
Key specifications for M2721B: Head Height: 0.327 INCHES MAXIMUM IN; Fastener Length: 1.750 INCHES NOMINAL IN; Thread Length: 1.250 INCHES MINIMUM IN; Hardness Rating: 32.0 ROCKWELL C MINIMUM AND 38.0 ROCKWELL C MAXIMUM OVERALL. 16 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.