The Bolt,machine, cataloged under National Stock Number 5306-00-206-4387, is classified within Federal Supply Class 5306 (Bolts) of the Hardware and Abrasives group. The manufacturer of record is Twin Disc, Incorporated Dba Twin Disc Mid-Atlantic. Government technical data includes 17 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through both NSN and commercial part number lookups. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5306-00-206-4387 |
| Primary Part Number | M431 |
| Item Name | Bolt,machine |
| FSC / FSG | 5306 / 53 — Bolts |
| Manufacturer | Twin Disc, Incorporated Dba Twin Disc Mid-Atlantic |
| Status | ACTIVE |
| Head Height | 0.302 INCHES MINIMUM AND 0.323 INCHES MAXIMUM IN |
| Fastener Length | 1.500 INCHES NOMINAL IN |
| Thread Length | 1.062 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 |
| Departure From Cited Designator | AS MODIFIED BY HD DIM. AND THD LENGTH |
| Grip Length | 1.062 INCHES MINIMUM IN |
| Width Between Flats | 0.725 INCHES MINIMUM AND 0.750 INCHES MAXIMUM IN |
| 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 |
|---|---|
| M431 PRIMARY | Twin Disc, Incorporated Dba Twin Disc Mid-Atlantic (USA) |
| Reference | Meaning |
|---|---|
| S1585 | 5/9 Secondary reference Pettibone Westrac |
| MIL-B-1222 | 4/1 Identification reference U.S. Government activity |
| S1585 | C/1 Advisory reference — outside the item-of-supply concept Zf Industrieantriebe Witten Gmbh |
NSN 5306-00-206-4387 is a Bolt,machine, manufactured by Twin Disc, Incorporated Dba Twin Disc Mid-Atlantic, classified under FSC 5306, Bolts. Status: active.
NSN 5306-00-206-4387 has 1 manufacturer part number on file: M431 (Twin Disc, Incorporated Dba Twin Disc Mid-Atlantic).
1 possible match (shared part number, not a government interchangeability claim): 5305-00-273-9289. Verify interchangeability with system specifications before substitution.
Key specifications for M431: Head Height: 0.302 INCHES MINIMUM AND 0.323 INCHES MAXIMUM IN; Fastener Length: 1.500 INCHES NOMINAL IN; Thread Length: 1.062 INCHES MINIMUM IN; Hardness Rating: 32.0 ROCKWELL C MINIMUM AND 38.0 ROCKWELL C MAXIMUM OVERALL. 17 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.