SAE AS9554F-2024
SCREW, MACHINE - DOUBLE HEXAGON EXTENDED WASHER HEAD, CORROSION- AND HEAT-RESISTANT STEEL, UNS S66286, 130 KSI MIN, .1380-40 UNJF-3A

Standard No.

SAE AS9554F-2024

Release Date

2024

Published By

Society of Automotive Engineers (SAE)  US  /  SAE

Latest

SAE AS9554F-2024

Introduction

AS9554 Standard Technical Analysis

This specification defines the manufacturing requirements for double hexagonal washer head machine screws for aviation applications. Made of UNS S66286 heat-resistant and corrosion-resistant steel, it has a minimum tensile strength of 130 ksi and a thread size of .1380-40 UNJF-3A. This standard is derived from a revised version of US Military Standard MS9554D, and the latest revision, as of 2024, aligns with the requirements of ASME Y14.5-2018.

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Core Parameter Comparison Table

Part Number	Length L(in)	Gasket Thickness K(in)	Mass (lb/100)
MS9554-02	0.240-0.260	0.058-0.078	0.297
MS9554-30	1.990-2.010	1.414-1.474	0.913

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Material Property Requirements

Steel must comply with AMS5731 standard, with a composition similar to UNS S66286, and must pass:

• Fluorescent Penetrant Inspection: ASTM E1417 Type 1 Sensitivity
• Surface Roughness: 125μin Ra (ASME B46.1)
• Edge Finish: 0.003-0.015 inch chamfer

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Military Standard Conversion Notes

SAE explicitly states that this standard retains the part numbering system of the original military document, but removes the mandatory QPL (Qualified Products List) requirement. Department of Defense contracts can continue to implement the original QPL regulations.

Major technical changes include:

1. Thread lead-in chamfer changed to AS1132 specification
2. Weight reduction hole configuration updated to AS1132
3. Head fillet marking changed to "CR"

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Implementation Recommendations

1. Inventory Management: Consumption of inventory parts manufactured using older standards is permitted

2. Inspection Focus: The head cold rolling process is not mandatory for parts from MS9554-02 to 10

3. Dimension Datum: Parts 2-10 need to use the thread pitch diameter (Datum Z) instead of the conventional datum