The Washer,flat, cataloged under National Stock Number 5310-01-451-7945, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is Lockheed Martin Corporation Div Rotary and Mission Systems. Government technical data includes 9 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 3 items share a part number with this NSN in the catalog (possible match — not a government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 | 5310-01-451-7945 |
| Primary Part Number | 197A203-2 |
| Item Name | Washer,flat |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Lockheed Martin Corporation Div Rotary and Mission Systems |
| Status | ACTIVE |
| Surface Treatment Document and Classification | MIL-F-14072 TYPE 2 MIL SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Overall Diameter | 1.375 INCHES NOMINAL IN |
| Cross-Sectional Shape Style | RECTANGULAR |
| Surface Treatment | PASSIVATE OVERALL |
| Peripheral Shape Style | ROUND |
| Material | STEEL COMP 304 OVERALL |
| Center Hole Shape Style | ROUND |
| Hole Diameter | 0.178 INCHES MINIMUM AND 0.198 INCHES MAXIMUM IN |
| Thickness | 0.062 INCHES NOMINAL IN |
| 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 |
|---|---|
| 197A203-2 PRIMARY | Lockheed Martin Corporation Div Rotary and Mission Systems (USA) |
| Reference | Meaning |
|---|---|
| 84-31 | 5/1 Secondary reference Loctite Corp |
NSN 5310-01-451-7945 is a Washer,flat, manufactured by Lockheed Martin Corporation Div Rotary and Mission Systems, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-01-451-7945 has 1 manufacturer part number on file: 197A203-2 (Lockheed Martin Corporation Div Rotary and Mission Systems).
3 possible matches (shared part number, not a government interchangeability claim): 6515-01-505-3181, 6515-01-565-0188, 5975-01-678-0561. Verify interchangeability with system specifications before substitution.
Key specifications for 197A203-2: Surface Treatment Document and Classification: MIL-F-14072 TYPE 2 MIL SPEC SINGLE TREATMENT RESPONSE OVERALL; Overall Diameter: 1.375 INCHES NOMINAL IN; Cross-Sectional Shape Style: RECTANGULAR; Surface Treatment: PASSIVATE OVERALL. 9 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.