Cross reference · NAS (Aerospace Industries Association) · Plate self-locking nut

NAS1791C cross referenceSPS F18421L, Howmet F49249E, Boeing ST3M

NAS1791C is a plate self-locking nut series on 46 government stock numbers. Its closest equivalents are SPS F18421L, Howmet F49249E, Boeing ST3M. Each one is labeled with how strong the evidence is.

Equivalents in the government catalog

46 stock numbers

Catalog-only listings need engineering approval before you substitute.

Manufacturers

  • F18421LSPS TechnologiesCatalog only, needs approvalon 12 of 46 stock numbers, 12 sizes
  • F49249EHowmet Fastening SystemsCatalog only, needs approvalon 12 of 46 stock numbers, 13 sizes
  • NS202041SPS TechnologiesCatalog only, needs approvalon 12 of 46 stock numbers, 12 sizes
  • F18421ESNACatalog only, needs approvalon 7 of 46 stock numbers, 7 sizes
  • F49249Howmet Fastening SystemsCatalog only, needs approvalon 4 of 46 stock numbers, 4 sizes
2 more on one stock number each: LACR53M, N202041
  • LACR53MHowmet Fastening SystemsCatalog only, needs approvalon 1 of 46 stock numbers
  • N202041SPS TechnologiesCatalog only, needs approvalon 1 of 46 stock numbers

Airframer and OEM drawings

  • ST3MBoeingCatalog only, needs approvalon 12 of 46 stock numbers, 13 sizes
  • 3929ASUS NavyCatalog only, needs approvalon 3 of 46 stock numbers, 3 sizes

Plus 3 reference numbers whose issuer SpecLok does not identify (distributors and catalog agencies are not named).

Get quotes for NAS1791C

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

Install tooling

SpecLok has no catalog family for NAS1791C. Tooling for the equivalents:

None of the equivalents is in the SpecLok catalog yet.

What the government paid

DLA awards on 15 of 46 stock numbers, 82 awards from 2023-01-11 to 2026-06-22.

Latest award per stock number: $1.01 to $9.40 each.

DLA production lead time: 146 to 599 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

46 stock numbers
Part numbers DLA FLIS lists for NAS1791C and its equivalents, by stock number
NSNNAS1791CF18421LF49249EF18421ST3MLast DLA price
5310-00-379-4633NAS1791C3-1F18421L1-3F49249E3-1F18421-1-3ST3M443-3A1
5310-00-143-0358NAS1791C3-2F18421L2-3F49249E3-2F18421-2-3ST3M443-3A2$1.01 2025-10
5310-01-334-7938NAS1791C3-3$1.56 2026-06
5310-01-328-2043NAS1791C3-4$1.60 2025-09
5310-01-334-7937NAS1791C3-5$1.95 2025-12
5310-00-283-4616NAS1791C3-6F18421L6-3F49249E3-6ST3M443-3A6$4.61 2026-05
5310-00-283-4618NAS1791C4-1F18421L1-4F49249E4-4-1F18421-1-4ST3M443-4A1$2.07 2024-12
5310-00-283-4619NAS1791C4-2F18421L2-4F49249E4-2F18421-2-4ST3M443-4A2
5310-01-090-5559NAS1791C4-3F18421L3-4F49249E4-3ST3M443-4A3$3.96 2026-05
5310-01-090-6367NAS1791C4-4F18421L4-4F49249E4-4F18421-4-4ST3M443-4A-4$2.45 2026-06
5310-01-657-4708NAS1791C4-4
5310-01-090-5556NAS1791C4-5F18421L5-4F49249E4-5ST3M443-4A5$4.84 2023-11
5310-00-283-7522NAS1791C4-6F18421L6-4F49249E4-6F18421-6-4ST3M443-4A6
5310-01-098-6193NAS1791C5-1F18421L1-5F49249E5-1ST3M443-5A1$3.66 2026-03
5310-01-459-6543NAS1791C5-2
Show 31 more sizes
More sizes
NSNNAS1791CF18421LF49249EF18421ST3MLast DLA price
5310-01-356-5103NAS1791C5-3$8.85 2026-05
5310-00-283-4635NAS1791C5-4F18421L4-5F49249E5-4F18421-4-5ST3M443-5A4$9.40 2023-11
5310-01-251-4223NAS1791C5-5F18421L5-5F49249E5-5ST3M443-5A5
5310-01-713-3732NAS1791C5-6
5310-01-659-4382NAS1791C6-1
5310-01-713-3745NAS1791C6-2
5310-01-727-4228NAS1791C6-3
5310-01-569-0736NAS1791C6-4
5310-01-713-3888NAS1791C6-5
5310-01-727-4227NAS1791C6-6
5310-01-585-8343NAS1791C08-1
5310-01-680-9141NAS1791C08-3$3.13 2025-04
5310-01-718-3114NAS1791C08-4
5310-01-691-7292NAS1791C08-1NP
5310-01-695-1387NAS1791C08-2NP
5310-01-542-9929NAS1791C3-1K
5310-01-723-6709NAS1791C3-1KNP
5310-01-663-3724NAS1791C3-1N
5310-01-663-8647NAS1791C3-1NP
5310-01-565-6507NAS1791C3-2K
5310-01-587-3095NAS1791C3-2K
5310-01-331-6292NAS1791C3-2NP
5310-01-342-7249NAS1791C3-3K$6.84 2024-03
5310-01-332-6511NAS1791C3-3NP$2.65 2024-09
5310-01-343-3186NAS1791C3-4K
5310-01-691-7288NAS1791C4-1NP
5310-01-723-6476NAS1791C4-2P
5310-01-664-8565NAS1791C4-4NP
5310-01-358-6676NAS1791C4-6K
5310-01-700-8339NAS1791C5-2NP
5310-01-663-1325NAS1791C6-1NP

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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