The Nut,self-Locking,castellated,hex, cataloged under National Stock Number 5310-01-015-5728, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is Sps Technologies, Llc Dba PB Fasteners. Government technical data includes 13 specifications, cited from the U.S. Government catalog. The record lists 2 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 5 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 4 items share a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5310-01-015-5728 |
| Primary Part Number | 55136-428 |
| Item Name | Nut,self-Locking,castellated,hex |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Sps Technologies, Llc Dba PB Fasteners |
| Status | ACTIVE |
| Width Across Flats | 0.435 INCHES NOMINAL IN |
| Thread Series | UNJS |
| Hardness Rating | 26.0 ROCKWELL C MAXIMUM |
| Material Document and Classification | AMS 5020 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| Thread Direction | RIGHT-HAND |
| Nominal Thread Size | 0.250 INCHES IN |
| Locking Feature | FREE-RUNNING ALL METAL DESIGN |
| Nut Height | 0.320 INCHES NOMINAL IN |
| Nut Style | CASTELLATED, HEXAGON |
| Thread Class | 3B |
| Thread Quantity Per Inch | 28 |
| Material | STEEL COMP 11L37 OVERALL |
| Bearing Surface Type | 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 |
|---|---|
| 55136-428 PRIMARY | Sps Technologies, Llc Dba PB Fasteners (USA) |
| 753949 | Rtx Corporation Dba Pratt & Whitney Div Pratt &whitney (USA) |
| Reference | Meaning |
|---|---|
| SD.300.55135 | 5/9 Secondary reference Sps Technologies, Llc Dba PB Fasteners |
| 184909 | 5/9 Secondary reference Harvard Industries Inc |
| Z2336-048 | 5/9 Secondary reference Sps Technologies Inc |
| 184909 | 5/9 Secondary reference Rtx Corporation Dba Pratt & Whitney Div Pratt &whitney |
| SD.300.55135 | 5/9 Secondary reference U.S. Government activity |
NSN 5310-01-015-5728 is a Nut,self-Locking,castellated,hex, manufactured by Sps Technologies, Llc Dba PB Fasteners, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-01-015-5728 has 2 manufacturer part numbers on file: 55136-428 (Sps Technologies, Llc Dba PB Fasteners), 753949 (Rtx Corporation Dba Pratt & Whitney Div Pratt &whitney).
4 possible matches (shared part number, not a government interchangeability claim): 6750-01-428-0985, 5995-01-702-8123, 5995-01-702-8124. Verify interchangeability with system specifications before substitution.
Key specifications for 55136-428: Width Across Flats: 0.435 INCHES NOMINAL IN; Thread Series: UNJS; Hardness Rating: 26.0 ROCKWELL C MAXIMUM; Material Document and Classification: AMS 5020 ASSN STD SINGLE MATERIAL RESPONSE OVERALL. 13 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.