NAS43HT3-86 – Textron Aviation OEM Heat-Treated Steel Sleeve Spacer
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Overview
The NAS43HT3-86 is a high-strength, precision sleeve spacer that holds dual authority as a component built to the exacting National Aerospace Standard (NAS43) and as a genuine Textron Aviation Original Equipment Manufacturer (OEM) part. This component is engineered to maintain a precise axial distance between parts mounted on a 3/16-inch diameter bolt, while also serving as a critical bearing surface and load-distributing member. The "HT" designation signifies it is fabricated from Heat-Treated alloy steel, providing significantly higher compressive strength and durability.
As a genuine Textron Aviation part, this spacer is guaranteed to meet the specific material, heat treatment, and dimensional tolerances required for flight-critical applications on Cessna, Beechcraft, and Hawker aircraft. It ensures correct assembly geometry, prevents over-compression of softer materials, and provides a hardened surface for rotating components or fasteners.
Key Features
Genuine Textron Aviation OEM Part: Guarantees the part is the factory-specified and fully certified component, ensuring correct performance and airworthiness.
National Aerospace Standard Compliance: Manufactured and inspected to meet all requirements of NAS43, ensuring interchangeability, quality, and traceability.
Heat-Treated Alloy Steel: Fabricated from high-strength alloy steel (e.g., 4130, 4140) and heat-treated for superior compressive strength and wear resistance.
Precision Dimensions: Machined to exacting tolerances for Inside Diameter (ID), Outside Diameter (OD), and Length, ensuring a perfect fit and correct spacing (5-3/8").
Load Distribution & Bearing Surface: Distributes fastener clamping loads and provides a durable bearing surface.
Cadmium Plated for Corrosion Resistance: Coated with cadmium per QQ-P-416 for excellent corrosion protection.
Technical Specifications
Part Number: NAS43HT3-86
Component Type: Sleeve Spacer
OEM Authority: Textron Aviation
Governing Specification: NAS43
Material: Alloy Steel (e.g., 4130, 4140), Heat Treated.
Finish: Cadmium Plate per QQ-P-416, Type II, Class 2.
Nominal Inside Diameter (ID): For 3/16 inch bolt/shaft (0.190 inches).
Outside Diameter (OD): 5/16 inch (0.3125 inches).
Length (L): 5-3/8 inches (5.375 inches).
Aircraft Compatibility
As a Textron Aviation OEM part and a NAS standard, this spacer is used in numerous applications across their aircraft fleet and the wider aerospace industry.
Primary Textron Aviation Platforms:
Cessna Piston Aircraft
Beechcraft Piston Aircraft
Cessna Caravan Series
Cessna Citation Business Jets
Beechcraft King Air Series
Hawker Business Jets
General Aerospace Usage: Common across the industry where a high-strength NAS43HT3-86 spacer is specified.
Note: Verification of applicability is the responsibility of the installer. Always consult the current version of the aircraft's Illustrated Parts Catalog (IPC) to confirm part number eligibility for a specific location.
Applications
Maintaining precise spacing between structural members, brackets, and fittings in bolted joints.
Acting as a sleeve bearing within pivot points for control linkages or landing gear components.
Preventing the crushing of lightweight structures when fastener clamp loads are applied.
Establishing correct edge distance or alignment for components mounted on longer bolts.
Why Choose this NAS43HT3-86?
This component provides the dual assurance of meeting the public NAS aerospace standard and the specific endorsement of Textron Aviation. The correct spacing and load distribution within a bolted joint are critical. Using the genuine OEM part guarantees the component is made from the specified high-strength, heat-treated steel and machined to the precise dimensions required by Textron engineers. Substituting a non-certified spacer, or one made from a softer material, can lead to joint failure, compromising airworthiness.
The engineering function of the NAS43HT3-86 spacer often involves maintaining edge distance and providing bearing support in bolted joints, particularly through composite materials or thin-walled structures. Edge distance (the distance from the center of a fastener hole to the edge of the part) is critical for preventing tear-out failures. A spacer ensures that the clamping force is applied further away from the edge, effectively reinforcing the area. Furthermore, the heat-treated steel composition provides a high bearing strength. When a bolt is loaded in shear, it exerts a bearing stress on the material surrounding the hole. The high compressive yield strength of the heat-treated steel spacer prevents the hole from elongating or yielding under these bearing loads, which is particularly important when bolting through softer materials like aluminum or composites which have lower bearing allowables. This prevents joint loosening and ensures the load is transferred efficiently through the fastener.
Note: This is a flight-critical hardware component. Installation must be performed by a certified mechanic. The spacer must be the correct length and diameter for the application as specified in the maintenance manual or IPC. Ensure the spacer is installed cleanly, without burrs, and that mating surfaces are flush.
Documentation
The National Aerospace Standard governing this part is publicly available through standards organizations or suppliers. OEM-specific application data is contained within the Textron Aviation maintenance and parts manuals.
Defense Logistics Agency - NAS43 Document (Reference): https://everyspec.com/NAS/NAS-0-99/NAS43_Rev_11_55740/