The Nut,self-Locking,hexagon, cataloged under National Stock Number 5310-00-243-8238, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is Esna, Llc. Government technical data includes 14 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5310-00-243-8238 |
| Primary Part Number | 99NM38 |
| Item Name | Nut,self-Locking,hexagon |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Esna, Llc |
| Status | ACTIVE |
| Width Across Flats | 0.240 INCHES MINIMUM AND 0.252 INCHES MAXIMUM IN |
| Thread Series | UNIFIED NATIONAL COARSE (UNC) |
| Material Document and Classification | MIL-M-20693 MIL SPEC ALL MATERIAL RESPONSES LOCKING INSERT |
| Material Document and Classification | QQ-B-626 FED SPEC SINGLE MATERIAL RESPONSE NUT |
| Thread Direction | RIGHT-HAND |
| Nominal Thread Size | 0.252 INCHES IN |
| Locking Feature | PREVAILING TORQUE WITH NONMETALLIC INSERT |
| Nut Height | 0.133 INCHES MINIMUM AND 0.153 INCHES MAXIMUM IN |
| Nut Style | HEXAGON |
| Thread Class | 2B |
| Thread Quantity Per Inch | 48 |
| Material | PLASTIC POLYHEXAMETHYLENE AMIDE OR PLASTIC POLYCAPROLACTAM LOCKING INSERT |
| Material | COPPER ALLOY NUT |
| Bearing Surface Type | FLAT OR CHAMFERED |
| 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 |
|---|---|
| 99NM38 PRIMARY | Esna, Llc (USA) |
| Reference | Meaning |
|---|---|
| 333-0334-000 | 5/2 Secondary reference U.S. Government activity |
| 99NM38 | 5/9 Secondary reference Harvard Industries Inc |
NSN 5310-00-243-8238 is a Nut,self-Locking,hexagon, manufactured by Esna, Llc, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-00-243-8238 has 1 manufacturer part number on file: 99NM38 (Esna, Llc).
Key specifications for 99NM38: Width Across Flats: 0.240 INCHES MINIMUM AND 0.252 INCHES MAXIMUM IN; Thread Series: UNIFIED NATIONAL COARSE (UNC); Material Document and Classification: MIL-M-20693 MIL SPEC ALL MATERIAL RESPONSES LOCKING INSERT; Material Document and Classification: QQ-B-626 FED SPEC SINGLE MATERIAL RESPONSE NUT. 14 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.