PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

21685Washer,special

Mason Electric Co. Dba Mason Controls · NSN 5310-00-045-7521 · FSC 5310 · No Item Name Available
Verified by PartsTable
NSN 5310-00-045-7521 — this item is cataloged by the U.S. Government under National Stock Number 5310-00-045-7521. Primary manufacturer part number: 21685.
Features
  • Washer,special — FSC 5310
  • 3 verified cross-references
  • Primary manufacturer: Mason Electric Co. Dba Mason Controls
Applications
  • Structural fastening and assembly
  • Equipment mounting
  • Panel and housing attachment
General Description

The Washer,special, cataloged under National Stock Number 5310-00-045-7521, is classified within Federal Supply Class 5310 (No Item Name Available) of the Hardware and Abrasives group. The primary manufacturer of record is Mason Electric Co. Dba Mason Controls. This item has 3 commercial cross-references from 3 manufacturers, enabling identification through both NSN and commercial part number lookups. 7 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Catalog Facts
Item NameWasher,special
FSC / FSG5310 — No Item Name Available (FSG 53)
ManufacturersUnison Industries Llc (CAGE 59501); Mason Electric Co. Dba Mason Controls (CAGE 81579); Amphenol Corp Div Amphenol Aerospace Operations (CAGE 77820)
Technical Specifications
ParameterValue
NSN5310-00-045-7521
Primary Part Number21685
Item NameWasher,special
FSC / FSG5310 / 53 — No Item Name Available
ManufacturerMason Electric Co. Dba Mason Controls
StatusACTIVE
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 7
5330-00-115-384609762-C-P INTERCHANGEABLE
Seal,mechanical,rotary Shaft
Crane Pumps & Systems Pft Corp Div Crane Pumps & System Pft Corp.
4320-00-937-115321685 INTERCHANGEABLE
Base,pump
Industrial Technologies and Services Llc
5342-01-144-607721685 INTERCHANGEABLE
Bumper
Alliance Laundry Systems Llc
5998-01-228-2575 INTERCHANGEABLE
Circuit Card Assembly
6515-01-267-2735216.085 INTERCHANGEABLE
Screw,bone
Depuy Synthes Sales Inc Dba Depuy Synthes Trauma Div Depuy Synthes Sales, Inc., D/b/a Depuy Synthes Trauma
4730-01-326-807721685 INTERCHANGEABLE
Elbow,flange to Tube
Parker Hannifin Corporation Div Hydraulic Systems Division
2910-01-562-890821685 INTERCHANGEABLE
Fuel,engine Oil
Willard Marine, Inc.
Cross-Reference Index
Part NumberManufacturer
21685 Unison Industries Llc (USA)
21685 PRIMARY Mason Electric Co. Dba Mason Controls (USA)
21685 Amphenol Corp Div Amphenol Aerospace Operations (USA)
Related Parts
5330-00-115-3846INTERCHANGEABLE
SEAL,MECHANICAL,ROTARY SHAFT
09762-C-P
4320-00-937-1153INTERCHANGEABLE
BASE,PUMP
21685
5342-01-144-6077INTERCHANGEABLE
BUMPER
21685
5998-01-228-2575INTERCHANGEABLE
CIRCUIT CARD ASSEMBLY
6515-01-267-2735INTERCHANGEABLE
SCREW,BONE
216.085
4730-01-326-8077INTERCHANGEABLE
ELBOW,FLANGE TO TUBE
21685
2910-01-562-8908INTERCHANGEABLE
FUEL,ENGINE OIL
21685

Frequently Asked Questions

What is NSN 5310-00-045-7521?

NSN 5310-00-045-7521 is a Washer,special, manufactured by Mason Electric Co. Dba Mason Controls, classified under FSC 5310 (No Item Name Available). Status: active.

What are the part numbers for NSN 5310-00-045-7521?

NSN 5310-00-045-7521 has 3 cross-referenced part numbers: 21685 (Unison Industries Llc), 21685 (Mason Electric Co. Dba Mason Controls), 21685 (Amphenol Corp Div Amphenol Aerospace Operations).

What NSN replaces 5310-00-045-7521?

There are 7 known substitutes for 5310-00-045-7521: 5330-00-115-3846, 4320-00-937-1153, 5342-01-144-6077 and 4 more. Verify interchangeability with system specifications before substitution.

Validated with multiple authoritative sources, including Government, OEM, and Certified sources.
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