SAE MA4177A-2020 PDF

Full title and description

St SAE MA4177A-2020 — NUT, SELF LOCKING - HEX EXTENDED WASHER UNS N07001, SILVER PLATE, MJ THD, METRIC. This SAE aerospace specification defines the form, fit, material, finish and basic acceptance requirements for a metric self‑locking hex nut with extended washer manufactured from UNS N07001 and furnished with a silver plate finish for use on MJ (metric) threads.

Abstract

SAE MA4177A-2020 specifies requirements for a self‑locking hex nut with an integrally formed extended washer, intended for aerospace applications where high‑temperature capability and corrosion resistance are required. The document identifies the base material (UNS N07001 — a nickel‑base superalloy commonly known as Waspaloy), plating/finish (silver plate), thread form (metric MJ), dimensional tolerances, mechanical/locking characteristics and inspection/acceptance provisions necessary to ensure interchangeability and performance in critical assemblies.

General information

• Status: Active (published revision).
• Publication date: October 1, 2020 (MA4177A-2020 revision).
• Publisher: SAE International (Society of Automotive Engineers / SAE Aerospace Standards).
• ICS / categories: Aerospace standards; Fasteners / Mechanical components; SAE MA series (aerospace fasteners).
• Edition / version: MA4177A-2020 (Revision A, 2020).
• Number of pages: 2 (concise technical specification).

Scope

This standard applies to metric self‑locking hex nuts with an extended washer configuration manufactured from UNS N07001 and finished with silver plating. It establishes dimensional requirements, material and heat‑treatment references, surface finish/plating requirements, mechanical/locking feature performance, inspection and acceptance criteria, and marking/packaging instructions for parts intended for aerospace use. It is intended for use where the mechanical and environmental properties of UNS N07001 and a silver plate finish are required for reliability and corrosion resistance in service.

Key topics and requirements

• Designation and identification: part numbering and designation as SAE MA4177A-2020.
• Base material: UNS N07001 (nickel‑base superalloy, commonly used in aerospace fasteners for high‑temperature strength and corrosion resistance).
• Geometry and dimensions: hex nut with extended washer form, metric (MJ) thread sizes and tolerances.
• Locking feature: specified self‑locking design and required locking performance (torque/prevailing torque characteristics).
• Surface finish and plating: silver plate requirements, acceptable thickness/appearance, and corrosion performance expectations.
• Mechanical properties and acceptance testing: basic strength/torque criteria, proof load or functional tests as applicable.
• Inspection, sampling and acceptance criteria: visual, dimensional and functional checks required for lot acceptance.
• Marking and packaging: required part marking and packing to preserve part integrity for aerospace supply chains.

Typical use and users

Users include aerospace OEMs, aircraft and engine manufacturers, fastener designers and manufacturers, procurement specialists for aerospace components, maintenance/repair organizations and quality engineers responsible for conformity of critical fasteners. Typical applications are structural and engine fastenings where high temperature strength, corrosion resistance and reliable locking are required.

Related standards

Related documents include previous revisions of the same SAE MA4177 series, other SAE MA-series fastener specifications, and complementary aerospace fastener material and plating specifications. In practice this standard is used alongside aerospace material specifications (AMS) and general fastener standards (ISO/ASTM/SAE) that govern thread forms, plating processes and test methods for aerospace hardware.

Keywords

SAE MA4177A-2020, self‑locking nut, hex extended washer, UNS N07001, Waspaloy, silver plate, MJ thread, metric fastener, aerospace fastener, locking nut.

FAQ

Q: What is this standard?

A: SAE MA4177A-2020 is an SAE aerospace specification that defines the requirements for a metric self‑locking hex nut with an extended washer made from UNS N07001 and finished with a silver plate; it is intended for aerospace applications.

Q: What does it cover?

A: It covers designation, material (UNS N07001), dimensions and tolerances for the hex extended washer nut, locking performance, plating/finish requirements, inspection and acceptance criteria, marking and packaging instructions.

Q: Who typically uses it?

A: Aerospace OEMs, fastener manufacturers, procurement and quality engineers, and maintenance/repair organizations that require qualified, high‑performance locking nuts for aircraft and engine applications.

Q: Is it current or superseded?

A: The document shown is the 2020 revision (MA4177A-2020). It is published as the MA4177A revision; users should confirm current status with SAE International or an official standards distributor if absolute up‑to‑date confirmation is required for procurement or certification.

Q: Is it part of a series?

A: Yes — it belongs to the SAE MA series of aerospace fastener standards (MA-prefixed documents) that collectively define materials, forms and requirements for a variety of nuts, bolts and related hardware used in aerospace assemblies.

Q: What are the key keywords?

A: Self‑locking nut, extended washer, hex nut, UNS N07001, Waspaloy, silver plate, metric MJ thread, aerospace fastener, SAE MA4177A.