The Washer,flat, cataloged under National Stock Number 5310-01-250-5255, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is Roller Bearing Co of America, Inc Div Pic Design. Government technical data includes 10 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through both NSN and commercial part number lookups. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 3 items share a part number with this NSN in the catalog (possible match — not a government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 | 5310-01-250-5255 |
| Primary Part Number | B3-50 |
| Item Name | Washer,flat |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Roller Bearing Co of America, Inc Div Pic Design |
| Status | ACTIVE |
| Surface Treatment Document and Classification | QQ-P-35,TY 2 FED SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Overall Diameter | 0.305 INCHES MINIMUM AND 0.315 INCHES MAXIMUM IN |
| Material Document and Classification | ASTM A582 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| Cross-Sectional Shape Style | RECTANGULAR |
| Surface Treatment | PASSIVATE OVERALL |
| Peripheral Shape Style | ROUND |
| Material | STEEL COMP 303 OVERALL |
| Center Hole Shape Style | ROUND |
| Hole Diameter | 0.206 INCHES MINIMUM AND 0.211 INCHES MAXIMUM IN |
| Thickness | 0.019 INCHES MINIMUM AND 0.021 INCHES MAXIMUM 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 |
|---|---|
| B3-50 PRIMARY | Roller Bearing Co of America, Inc Div Pic Design (USA) |
| Reference | Meaning |
|---|---|
| 4300001-26 | C/1 Advisory reference — outside the item-of-supply concept The Boeing Company Div Defense |
| 4300001-26 | 7/9 Vendor item drawing reference Mcdonnell Douglas Corp Mcdonnell Douglas Aerospace Opns West |
| 10110216 | 6/9 Informative reference only Nimikkeistokeskus Ncb Finland |
NSN 5310-01-250-5255 is a Washer,flat, manufactured by Roller Bearing Co of America, Inc Div Pic Design, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-01-250-5255 has 1 manufacturer part number on file: B3-50 (Roller Bearing Co of America, Inc Div Pic Design).
3 possible matches (shared part number, not a government interchangeability claim): 5925-01-464-5338, 5961-01-486-1429, 4820-01-646-6753. Verify interchangeability with system specifications before substitution.
Key specifications for B3-50: Surface Treatment Document and Classification: QQ-P-35,TY 2 FED SPEC SINGLE TREATMENT RESPONSE OVERALL; Overall Diameter: 0.305 INCHES MINIMUM AND 0.315 INCHES MAXIMUM IN; Material Document and Classification: ASTM A582 ASSN STD SINGLE MATERIAL RESPONSE OVERALL; Cross-Sectional Shape Style: RECTANGULAR. 10 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.