AN525-10R14 - Phillips Washer Head Alloy Steel Aerospace Screw 10-32

AN525-10R14 – Phillips Washer Head Alloy Steel Aerospace Screw #10-32

Available now on the Airparts.aero Marketplace.

Overview

The AN525-10R14 is a mil-spec, washer head machine screw manufactured in accordance with the Aeronautical Standard (AN) specifications. This fastener is engineered for securing non-structural and semi-structural components throughout an aircraft where a broad clamping surface is required and shear and tensile loads are relatively low. The defining feature of the AN525 screw is its integrated washer head, which provides a large bearing surface to distribute clamping force, preventing damage to thin or soft materials like aluminum sheet, composites, or plastics.

Manufactured from heat-treated alloy steel and coated with cadmium for corrosion resistance, the AN525-10R14 is a high-quality, traceable fastener designed for reliability. The "10" in the part number designates a #10 diameter with a 32-thread-per-inch Unified National Fine (UNF) thread pitch, while the "R" indicates a recessed Phillips drive. The "-14" specifies the length of the screw. These screws are commonly found securing instrument panels, access covers, fairings, interior components, and light-duty brackets where the use of a separate washer is impractical or undesirable.

Key Features

• Mil-Spec Certification: Manufactured in strict accordance with AN525 and its superseding MS35214 standards.

• Integrated Washer Head: Provides a wide bearing surface to distribute load and protect the mating surface, eliminating the need for a separate washer.

• High-Strength Alloy Steel: Fabricated from heat-treated alloy steel for reliable strength in its intended applications.

• Corrosion Protection: Coated with Type II, Class 3 cadmium plating per QQ-P-416 for superior corrosion and galvanic resistance.

• Phillips Recess Drive: Allows for efficient, positive tool engagement, ideal for assembly and maintenance tasks.

• Full Traceability: Each production lot is fully traceable to its material and manufacturing certifications.

Technical Specifications

• Part Number: AN525-10R14

• Superseding Part Number: MS35214-49

• Component Type: Washer Head Machine Screw

• Basic Diameter: #10 (0.190 inches)

• Thread Specification: #10-32 UNF-2A

• Length: 14/16 inch (7/8 inch or 0.875") from under the head to the tip.

• Material: Alloy Steel, heat-treated.

• Finish: Cadmium Plated, Type II (Yellow Chromate), Class 3 per QQ-P-416.

• Head Type: Washer Head

• Drive Type: Phillips Recess ("R")

• Governing Specifications: AN525, MS35214

Aircraft Compatibility

• Universal Application: AN525 screws are standard hardware used across virtually all certified and experimental aircraft, including models from Textron Aviation (Cessna, Beechcraft), Piper, Cirrus, and countless others. The specific length (AN525-10R14) is called out in numerous assembly drawings for non-structural applications.

Note: The correct application of the AN525-10R14 must be verified against the aircraft's Illustrated Parts Catalog (IPC) or maintenance manual. Never substitute this screw for a structural bolt (e.g., AN3-AN20 series).

Applications

• Instrument Panel Installation: Securing flight instruments, gauges, and avionics to the panel structure.

• Access Cover & Fairing Attachment: Fastening inspection panels, wing root fairings, and other non-structural covers.

• Interior Components: Mounting interior panels, upholstery, and light fixtures.

• Light-Duty Brackets: Securing clamps (Adel clamps), wire bundles, and small brackets that are not part of the primary structure.

Why Choose AN525-10R14?

While it may appear to be a simple screw, the certified AN525-10R14 is manufactured and tested to standards far exceeding commercial hardware. Using a non-certified screw from a hardware store introduces risks of unknown material strength, improper heat treatment leading to brittleness, and inadequate corrosion protection. A failed screw, even in a non-structural application, can lead to component separation, causing hazards from unsecured equipment in the cockpit or creating aerodynamic disturbances if a fairing departs the aircraft. Using fully certified and traceable AN/MS hardware is the baseline for safe, airworthy maintenance.

The key engineering advantage of the AN525 washer head design is the optimization of bearing stress. Bearing stress (σb) is calculated as the applied load (P) divided by the bearing area (Ab). By integrating a washer into the head, the AN525 screw significantly increases the bearing area (Ab) compared to a standard pan or round head screw of the same shank diameter. This distribution of the clamping force over a larger area reduces the bearing stress on the substrate material. This is critically important in aerospace applications where thin aluminum sheets (e.g., 0.020" to 0.040" Alclad) are common. A conventional screw head could easily exceed the material's bearing yield strength, causing localized crushing, dimpling, or stress cracking around the fastener hole. The AN525 design mitigates this risk, ensuring a secure joint without compromising the integrity of the clamped material.

Note: The AN525-10R14 is intended for non-structural applications. It should not be used in primary structural joints or applications subjected to high shear or tensile loads. Installation must be performed by certified personnel in accordance with the aircraft's maintenance manual. Torque values should be referenced from standard charts like AC 43.13-1B for fine-thread screws, unless a specific value is provided by the manufacturer.

Documentation

• MS35214 (Superseding Standard): https://everyspec.com/MS-Specs/MS3-series/MS35214D_55319/

• QQ-P-416F (Plating): http://everyspec.com/QQ-SPECS/QQ-P/QQ-P-416F_22313/

• AN525 (Legacy Standard): Public-facing PDFs of the original AN catalog provide the foundational data, though the MS standard is now the governing document.