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MS27039-08-07 – Aerospace Screw
Available now on the Airparts.aero Marketplace.
Overview
The MS27039-08-07 is a high-strength, structural pan head screw manufactured in strict accordance with U.S. Military Standard specifications. This fastener is engineered for demanding aerospace applications where both high tensile strength and reliable clamping force are required. Unlike non-structural screws, the MS27039 series is fabricated from high-grade alloy steel and heat-treated to achieve a minimum tensile strength of 125,000 PSI, making it suitable for use in primary and secondary aircraft structures. Its pan head design offers a low profile with a high-strength-to-weight ratio, making it a versatile and essential piece of certified hardware for aircraft assembly and repair.
Key Features
- Structural Alloy Steel: Manufactured from high-grade steel alloys, such as 4037 or 8630, and properly heat-treated to achieve superior tensile and shear strength, qualifying it for use in structural applications.
- High-Strength Rating: Engineered to a minimum tensile strength of 125,000 PSI, providing the robust performance necessary to withstand the vibration, G-forces, and stress of flight.
- Pan Head Design: Features a low-profile pan head with a flat bearing surface, providing excellent clamping force without the added height of a washer head, ideal for use in tight spaces or on external surfaces.
- Corrosion-Resistant Plating: Plated with a cadmium and chromate finish per QQ-P-416, Type II, Class 3 specifications. This durable coating provides excellent protection against corrosion, a critical requirement for airframe longevity.
- Mil-Spec Certification: As a certified MS27039 part, it guarantees full traceability, dimensional accuracy, and material integrity, ensuring it meets the highest standards for airworthiness and safety.
Technical Specifications
- Standard: MS27039 (Screw, Machine, Pan Head, Structural, Cross-Recessed)
- Full Part Number: MS27039-08-07
- Material: Alloy Steel (e.g., 4037, 8630)
- Finish: Cadmium Plated, Type II, Class 3
- Head Style: Pan Head
- Drive Type: Phillips / Cross-Recess Type I
- Thread Specification: 8-32 UNC-3A
- Nominal Diameter: #8 (0.164 inches)
- Threads Per Inch: 32 (Coarse Thread)
- Length: 7/16 inches (0.438 inches nominal, 0.469 inches actual max), measured from under the head.
- Tensile Strength: 125,000 PSI minimum
Aircraft Compatibility
The MS27039-08-07 is a fundamental structural fastener used across all categories of aviation, from general aviation light aircraft to commercial airliners and military jets. Its use is dictated by the aircraft manufacturer's engineering drawings and parts catalogs.
- Common Applications:
- Attaching fuselage and wing skins to stringers and ribs.
- Securing access panels and fairings in high-stress areas.
- Mounting engine baffles and cowlings.
- Assembling airframe structural brackets and reinforcing plates.
Applications
The MS27039-08-07 screw is specifically chosen for its structural integrity in demanding scenarios:
- Shear and Tension Loads: Suitable for use in bolted joints that experience both shear (side-to-side) and tension (pulling) forces.
- Airframe Assembly: A primary fastener used in the construction and repair of the primary airframe structure.
- High-Vibration Areas: Its high strength and thread class (3A for a tighter fit) make it resistant to loosening in areas of significant vibration, such as firewalls and engine mounts.
Why Choose MS27039-08-07?
When assembling or repairing an aircraft structure, the integrity of every single fastener is paramount. Using a genuine, certified MS27039-08-07 structural screw is a mandatory requirement for airworthiness. This part guarantees a known, high level of strength and fatigue resistance that commercial-grade hardware cannot provide. Substituting a non-structural screw in a structural application can lead to joint failure under load, with potentially catastrophic consequences. For A&P mechanics, IA's, and aircraft manufacturers, relying on certified MS structural hardware is the only way to ensure the safety and integrity of the airframe.
Order Your MS27039-08-07 Screws Now
Build and repair with confidence using certified, high-strength structural hardware. Visit Airparts.aero to order your MS27039-08-07 structural screws today.
The MS27039 standard for structural screws is a critical specification in aerospace engineering, superseding older standards like NAS220. The designation as "structural" is not arbitrary; it signifies that the fastener has been subjected to rigorous manufacturing controls and heat treatment processes to ensure it can be used to transfer flight loads. The pan head design provides a compromise between the low-profile, drag-reducing shape of a countersunk head and the high clamping force of a hex head bolt. This makes it extremely versatile for attaching skins and components where a smooth exterior is desired, but the tensile strength of a true structural fastener is still required. The 3A thread class specifies a tighter tolerance than standard hardware, providing a more intimate fit between the screw and the nut or threaded hole, which is critical for distributing loads evenly and resisting fatigue in a high-vibration environment.
Note: Always verify the correct screw part number (including material, thread size, and length) from the applicable aircraft structural repair manual or Illustrated Parts Catalog (IPC). Use the correct size Phillips driver bit to avoid stripping the recess. Torque values for structural hardware are critical and must be referenced from the manufacturer's specific maintenance documentation.
