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SL4147CA10A – Shur-Lok Barrel Mount Assembly
Overview
The Shur-Lok SL4147CA10A is a flight-critical, OEM barrel mount assembly—federally cataloged as a forward mount barrel assembly under National Stock Number 1680-01-589-4077—engineered for high-tensile, heavy structural joint retention within advanced commercial aircraft airframes. Positioned at primary structural load paths, such as the forward engine pylon-to-wing attachment points or major fuselage fitting assemblies, this highly specialized mechanical fastener is designed to handle immense structural preloads. The assembly is composed of a high-strength cross-pinned barrel nut component combined with an integrated sheet metal retainer sleeve that ensures precise radial alignment inside the airframe's internal bore cavities.
Unlike standard external hex nut arrangements that demand substantial edge clearance and heavy, protruding flanges, the barrel-style configuration of the SL4147CA10A fits completely flush within a pre-drilled transverse bore. This allows a primary high-tensile mating bolt to pass longitudinally through the structural member and thread directly into the perpendicular cross-hole of the barrel nut. By shifting the fastening plane inside the component's cross-section, this architecture completely eliminates eccentric bending moments on the fastener shank, distributing immense clamp loads uniformly to prevent structural deflection under aggressive dynamic flight conditions.
For heavy aircraft maintenance depots, structural sheet metal specialists, and fleet procurement managers, sourcing an authentic factory-certified SL4147CA10A is an unyielding requirement for ensuring long-term airframe airworthiness. Sourcing this genuine Shur-Lok assembly protects your fleet against structural fatigue propagation and premature joint failure. Sourcing through Airparts.aero ensures complete metallurgical traceability, maintains compliance with rigid type-certificate data sheet (TCDS) standards, and guarantees a perfect mechanical interface that keeps your primary propulsion and wing fittings securely anchored.
Key Features
Flush Cross-Pin Configuration: Designed to fit completely within internal transverse bores, reducing exterior structural packaging profiles and eliminating the weight of heavy, protruding external attachment flanges.
Integrated Mechanical Retainer Sleeve: Outfitted with a precision-formed sheet metal cradle that clips into the structural guide hole, locking the barrel nut in perfect alignment with the incoming bolt path to prevent cross-threading during installation.
All-Metal Prevailing Torque Locking: Incorporates an integral, deformed-thread self-locking mechanism that provides continuous prevailing torque, preventing counter-rotational backing-off under continuous high-frequency engine harmonics.
Optimized Tension Joint Mechanics: Engineered specifically for pure axial tension joints, ensuring uniform distribution of multi-ton clamping forces across high-modulus structural member walls.
Erosion and Chemical Passivation: Finished with advanced aerospace barrier coatings to completely block galvanic oxidation when mated to dissimilar metals, including titanium fittings and clad aluminum structural webs.
Technical Specifications
Part Number: SL4147CA10A
Component Type: Barrel Mount Assembly / Forward Mount Barrel Nut Assembly
OEM Manufacturer: Shur-Lok Corporation (Precision Castparts Corp. / PCC Fasteners)
CAGE Code: 97393
National Stock Number (NSN): 1680-01-589-4077
Federal Supply Class (FSC): 1680 (Miscellaneous Aircraft Accessories and Components)
Material Composition: High-strength aerospace alloy steel (such as AISI 4340), A-286 corrosion-resistant steel, or Inconel 718 nickel-based superalloy (Exact proprietary material composition must be confirmed by the original OEM blueprint/drawings).
Finish: Cadmium-plated per AMS2400, passivated per AMS2700, or proprietary OEM dry-film lubricated coating.
Thread Profile: Precision internal cross-threaded execution with prevailing torque self-locking deformation.
Package Weight: 0.02 lbs (nominal unit weight).
Export Control Classification Number (ECCN): EAR99
Harmonized Tariff Schedule (HTS) / Schedule B Code: 7318160000 (Threaded nuts of iron or steel)
Certification Status: FAA Form 8130-3 Dual Release or OEM Certificate of Conformance (CoC) required for airframe integration.
Aircraft Compatibility
Boeing 737 Next Generation (NG) Series (Including 737-700, -800, and -900ER pylon/fuselage attachment fittings)
Boeing 737 MAX Series (737 MAX 8, MAX 9, MAX 10 powerplant structural integrations)
Boeing 777 & 787 Dreamliner Series (Select localized high-tensile structural fittings)
Note: The individual aircraft platform's Illustrated Parts Catalog (IPC) or specific airframe serial-number effectivity portal remains the final, absolute authority for part number verification, configuration control, and required installation quantities.
Applications
Primary Forward Engine Pylon Mounting: Secures the main forward structural pylon struts directly to the wing front spar wing fittings, neutralizing multi-directional engine thrust vectors.
Wing-to-Fuselage Major Attachment Joints: Acts as the primary internal mechanical constraint along high-stress station frames where the center wing box meets outer wing panels.
Heavy Structural Tail-Cone & Stabilizer Fitting: Locks primary vertical or horizontal stabilizer attachment fittings into the aft fuselage bulkhead matrix to resist aerodynamic shear loads.
Why Choose SL4147CA10A?
Integrating a genuine OEM Shur-Lok SL4147CA10A barrel mount assembly is paramount to safeguarding airframe longevity and avoiding catastrophic in-flight failures. Standard commercial-grade fasteners or non-authorized hardware lack the high-purity vacuum-arc remelted (VAR) grain alignment and strict heat-treatment tolerances needed to handle multi-ton cyclic tensile preloads. If an inferior substitute is introduced, it will experience rapid material relaxation or microstructural fatigue cracking under dynamic structural loads. This preload decay allows micro-slip to propagate across the structural fitting, resulting in hole elongation, fastener shear deformation, or eventual structural casing detachment. Sourcing certified OEM hardware through Airparts.aero guarantees total part traceability, eliminates the legal and mechanical risks of counterfeit parts, and ensures compliance with FAA and EASA regulatory airworthiness directives.
The operational physics of the SL4147CA10A barrel mount assembly focus on maximizing load path efficiency and optimizing multi-axial stress distribution within an internal cross-pin geometric framework. In high-consequence aerospace tension joints, traditional external threaded fasteners introduce severe eccentricities and localized stress-concentration factors due to the asymmetry of external flange load transfers. The SL4147CA10A eliminates these weaknesses by locating the nut internally within a precise transverse cylindrical bore. When the primary high-tensile bolt is torqued to its engineered preload, the barrel nut converts the purely axial tensile force into a uniform compressive bearing stress distributed across the internal surface area of the bore. Sourced from a precipitation-strengthened, fatigue-resistant alloy steel matrix, the assembly avoids anisotropic deformation and resists sub-critical material creep under continuous flight load variations. The integrated sheet metal retainer sleeve provides an essential mechanical constraint during assembly, while the precise crimped-thread profile introduces a controlled friction coefficient that guarantees a reliable prevailing torque. This structural distribution prevents thread shear deformation and arrests cyclic fatigue propagation, protecting the primary structural boundaries of the airframe.
Note: The SL4147CA10A barrel mount assembly is a flight-critical, single-use primary structural fastening element. Upon application of nominal installation torque, the internal prevailing torque threads and the integrated sheet metal retainer sleeve undergo intentional plastic-elastic deformation to achieve an unyielding mechanical lock. Attempting to clean, re-thread, or reuse a previously torqued barrel assembly introduces hazardous micro-fissures, fatigue vulnerability, and localized strain-hardening, risking sudden material fracturing under aerodynamic shear fields. Installation, bore inspection, and system rigging must be executed exclusively by an FAA-certified airframe mechanic or an authorized MRO facility in strict accordance with the appropriate Boeing Aircraft Maintenance Manual (AMM) Chapter 54 or specific Structural Repair Manual (SRM) directives.
