AN3-13A - Textron Aviation OEM Drilled Hex Head Machine Bolt

AN3H-13A – Textron Aviation OEM Drilled Head Hex Bolt

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Overview

The AN3H-13A is a high-strength, drilled-head hex bolt that holds dual authority as a component built to the exacting Air Force-Navy (AN) standard and as a genuine Textron Aviation Original Equipment Manufacturer (OEM) part. This fastener is engineered for the most critical joints where a positive, physical locking mechanism is required. Its defining feature is the set of holes drilled through the flats of the hexagonal head, which are designed for the installation of safety wire (lockwire) to prevent loosening from vibration.

As a component supplied through the Textron Aviation channel, this AN3H-13A bolt comes with the full assurance of OEM traceability and quality control. It is guaranteed to be the factory-specified hardware for maintaining the type-certified design and integrity of Cessna, Beechcraft, and Hawker aircraft. Fabricated from heat-treated alloy steel and finished with a protective cadmium plating, this bolt represents the highest standard of quality for a flight-critical fastener.

Key Features

• Textron Aviation OEM Certified: Supplied with the full traceability and quality assurance of Textron Aviation, guaranteeing it is the correct, factory-approved part for their fleet.

• Drilled Head for Lockwiring: The hexagonal head is cross-drilled to facilitate the installation of safety wire, creating a positive, anti-rotation locking mechanism.

• High-Tensile Alloy Steel: Forged from premium alloy steel and heat-treated to a minimum tensile strength of 125,000 PSI for maximum joint strength.

• Cadmium Plating: Coated with a sacrificial cadmium layer per QQ-P-416 for exceptional corrosion resistance and a consistent, low-friction bearing surface.

• Rolled Threads: Features #10-32 UNF-3A threads that are cold-rolled, a superior manufacturing process that significantly increases fatigue resistance.

• AN Standard Compliance: Fully conforms to the AN3H specification, ensuring the highest level of quality control for materials and dimensions.

Technical Specifications

• Part Number: AN3H-13A (commonly referred to as AN3-13A, Drilled Head)

• Component Type: Drilled Head Hexagonal Bolt

• OEM Authority: Textron Aviation

• Governing Specification: AN3H / NASM3H

• Material: Alloy Steel (e.g., 4140, 8740), heat-treated

• Minimum Tensile Strength: 125,000 PSI

• Finish: Cadmium Plate per QQ-P-416, Type II, Class 2

• Diameter: 3/16 inch (0.1875 inches)

• Nominal Length (under head to end): 1-3/8 inches (1.375 inches)

• Grip Length (Unthreaded Shank): 1 inch (1.000 inches)

• Thread Specification: #10-32 UNF-3A

Aircraft Compatibility

As a Textron Aviation OEM part, this fastener is specified in numerous locations across their entire product line. As an AN-standard bolt, its use is ubiquitous throughout the aerospace industry.

• Primary Textron Aviation Platforms:

  • Cessna Piston Aircraft (172, 182, 206, etc.)

  • Beechcraft Piston Aircraft (Bonanza, Baron)

  • Cessna and Beechcraft Turboprops (Caravan, King Air)

  • Cessna Citation Business Jets

  • Hawker Business Jets

• General Aerospace Usage: Used in virtually every class of aircraft for myriad applications requiring a drilled-head 3/16" bolt.

Note: Verification of applicability is the responsibility of the installer. Always consult the current version of the aircraft's Illustrated Parts Catalog (IPC) and maintenance manual to confirm part number eligibility.

Applications

• Powerplant: Securing engine accessories, magnetos, vacuum pumps, engine baffles, and exhaust system brackets where positive locking is required.

• Airframe: Attaching structural brackets, inspection panels, and system components located in areas of high vibration.

• Systems: Mounting hydraulic components, filter housings, and fluid line clamps.

Why Choose this AN3H-13A?

This component provides the dual assurance of meeting the public AN aerospace standard and the specific endorsement of Textron Aviation. This guarantees the bolt's mechanical properties, from the chemistry of its steel to the fatigue-resistance of its rolled threads. Using commercial-grade hardware in an aircraft application introduces an unacceptable risk of material fracture and joint failure. By choosing this OEM-certified AN bolt, you ensure the use of a traceable, airworthy component that maintains the aircraft's original design integrity.

The superior mechanical properties of the AN3H-13A bolt are a direct result of its material science and controlled heat treatment. It is forged from a chromium-molybdenum alloy steel, such as 4140, which is selected for its excellent hardenability, toughness, and fatigue strength. After machining, the bolt undergoes a precise quench and temper process. It is heated to an austenitizing temperature (approximately 1550°F) and then rapidly cooled (quenched) in oil, which transforms the steel's crystal structure into hard, brittle martensite. The critical next step is tempering, where the bolt is reheated to a lower, precisely controlled temperature (e.g., 800-1000°F). This process reduces the hardness slightly but significantly increases the material's toughness and ductility, resulting in a fine-tempered martensitic microstructure that provides the specified 125,000 PSI tensile strength along with the resilience needed to withstand the dynamic shear and tensile loads of flight without fracture.

Note: This is a flight-critical hardware component. Installation must be performed by a certified mechanic. A calibrated torque wrench must be used to apply the correct torque value specified in the maintenance manual to achieve proper preload. Safety wire must be installed in accordance with standard practices (e.g., AC 43.13-1B), ensuring it is new, clean, properly tensioned, and twisted correctly, with the pigtail bent back to prevent injury.

Documentation

The base standard for this part is maintained under the National Aerospace Standards (NASM). OEM-specific application and installation data is contained within the Textron Aviation maintenance and parts manuals.