Cross reference · ESNA · Hexagon self-locking nut

RM1801 cross referenceSPS 28FH, MS21045L

RM1801 is a ESNA hexagon self-locking nut series on 13 government stock numbers. Its closest equivalents are SPS 28FH, MS21045L. Each one is labeled with how strong the evidence is.

Equivalents in the government catalog

13 stock numbers

Catalog-only listings need engineering approval before you substitute.

Manufacturers

  • 28FHSPS TechnologiesCatalog only, needs approvalon 9 of 13 stock numbers, 9 sizes
  • SL2374SPS TechnologiesCatalog only, needs approvalon 6 of 13 stock numbers, 6 sizes
  • 38FHSPS TechnologiesCatalog only, needs approvalon 4 of 13 stock numbers, 4 sizes
  • SPS28GHSPS TechnologiesCatalog only, needs approvalon 3 of 13 stock numbers, 3 sizes

Standards

  • MS21045LMSCatalog only, needs approvalon 13 of 13 stock numbers, 10 sizes
1 more on one stock number each: NAS1022AM
  • NAS1022AMNASCatalog only, needs approvalon 1 of 13 stock numbers

Plus 12 reference numbers whose issuer SpecLok does not identify (distributors and catalog agencies are not named).

Get quotes for RM1801

Cited equivalents go on the request as acceptable alternates. Catalog-only listings do not.

Install tooling

SpecLok has no catalog family for RM1801. Tooling for the equivalents:

None of the equivalents is in the SpecLok catalog yet.

What the government paid

DLA awards on 3 of 13 stock numbers, 35 awards from 2023-02-16 to 2026-05-19.

Latest award per stock number: $0.37 to $28.75 each.

DLA production lead time: 134 to 423 days.

Per size in the table below.

DLA prices at DLA quantities, not a quote.Source

DLA award prices at DLA quantities and terms, not a commercial quote. Each award may bundle packaging, delivery and inspection terms that a commercial buy does not. Vendors are shown by CAGE code only.

Source: DLA FOIA Electronic Reading Room ↗, public FOIA releases. Files: 2023ContHist.zip/2023ContractHistory.txt, 2024ContHist.zip/2024ContractHistory.txt, contracthist2025.zip/contracthist2025.txt, 2026-09-16-1038_contracthist.zip/2026-09-16-1038_contracthist.txt.

Sizes by maker

13 stock numbers
Part numbers DLA FLIS lists for RM1801 and its equivalents, by stock number
NSNRM180128FHMS21045LLast DLA price
5310-00-857-4945RM1801-0228FH-1032MS21045L3$0.37 2025-12
5310-00-857-5558RM1801-4028FH-440MS21045L04
5310-00-857-5557RM1801-04828FH-428MS21045L4
5310-00-857-5559RM1801-05428FH-524MS21045L5
5310-00-857-5560RM1801-6228FH-632MS21045L06
5310-00-857-5562RM1801-08028FH-820MS21045L8
5310-00-857-5564RM1801-8228FH-832MS21045L08
5310-00-857-5565RM1801-098MS21045L9
5310-00-857-5566RM1801-108MS21045L10
5310-00-857-5975RM1801-126MS21045L12$28.75 2026-05
5310-00-211-9062RM1801-162MS21045L16$10.25 2025-06
5310-00-857-4948RM1801-069428FH-624MS21045L6
5310-00-857-5976RM1801-070U28FH-720UNMS21045L7

Each row is one National Stock Number and the part numbers DLA FLIS lists on it, as written there. A blank means FLIS lists no part in that series on the stock number, not that the size does not exist.

Sources and how to read this page.Details

Reference numbers the Federal Logistics Information System records against the same National Stock Number. A supply-catalog cross-reference, not an engineering-approved interchangeability: confirm against the controlling drawing or spec before substituting. Only equivalents marked cited have a manufacturer or government document, linked with each.

Source: DLA Federal Logistics Information System, via DLA PUB LOG ↗ (FLIS Data Electronic Reading Room ↗), data as of 2025-03-18 (March 2025 snapshot). Federal supply class 5310 Nuts and washers. Issuer names are SpecLok's reading of the filing CAGE code; distributors are not named. Compiled 2026-10-02.

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