BOLT, MACHINE (P/N an4-21) - New Surplus
P/N: an4-21
Category: Fasteners & Hardware
This product requires a custom quote. Please contact our sales team for pricing information or submit an RFQ (Request for Quote).
Available Inventory
| Condition | Stock |
|---|---|
| New Surplus | 135 Available |
Product Description
The AN4-21 is a 1/4-inch hex head machine bolt conforming to AN/NASM4 specifications. Manufactured from heat-treated alloy steel, this fastener features a 1/4-28 UNF thread and -21 length designation for aircraft structural applications. Used to secure airframe brackets, fittings, and components under tension or shear loads.
Installation requires proper grip length selection and torque application per FAA AC 43.13-1B standards and aircraft maintenance documentation. Suitable for general aviation and commercial aircraft assembly and repair.
Please note: Product descriptions are provided for informational purposes. Always refer to your aircraft's Illustrated Parts Catalog (IPC) to verify part compatibility and specifications.
Frequently Asked Questions
What is the BOLT, MACHINE (P/N an4-21)?
The AN4-21 is a 1/4-inch hex head machine bolt conforming to AN/NASM4 specifications. Manufactured from heat-treated alloy steel, this fastener features a 1/4-28 UNF thread and -21 length designation for aircraft structural applications.
Does the an4-21 meet AN/MS/NAS aviation specifications?
Aircraft hardware is manufactured to military and aviation specifications. The BOLT, MACHINE conforms to its applicable AN (Air Force-Navy), MS (Military Standard), or NAS (National Aerospace Standard) specification. Contact us for specific specification details.
What material is the an4-21 manufactured from?
Aviation hardware is available in various materials including cadmium-plated steel, stainless steel, aluminum alloy, and titanium depending on the application. Contact us for material certification and specifications for the an4-21.
Can I order the an4-21 in custom quantities?
Yes, we sell hardware in various quantities from single units to bulk lots. The BOLT, MACHINE is available in: New Surplus. Submit an RFQ for volume pricing or call (904) 998-9101 for quantity availability.