The NAS561P12-48 is a National Aerospace Standard (NAS561 series) slotted spring pin (roll pin) used in high-load mechanical retention and alignment applications in aircraft structures and assemblies. It is a larger-diameter, heavy-duty variant designed for components where higher shear strength and deeper engagement are required compared to smaller NAS561 pins.

This specific size corresponds to approximately 3/8" diameter and 3" length configuration, and it is commonly used in primary structural linkages such as landing gear assemblies, control system joints, and airframe attachment points where vibration resistance and secure mechanical locking are critical.

The slotted tubular design allows elastic compression during installation, creating constant radial spring force against the hole wall. This ensures secure retention without threads, while still allowing service removal during maintenance.

Key features include:

NAS561 heavy-duty slotted spring pin (roll pin)
Approx. size: 3/8" diameter × 3" length (NAS P12 series)
High shear-strength aerospace retention component
Designed for structural aircraft and landing gear applications
Self-retaining spring steel tubular construction
High vibration and fatigue resistance in cyclic loads
Typically made from hardened spring steel (carbon alloy range)
Corrosion-protected finish depending on supplier (cadmium/zinc/phosphate)
Used in airframe, control linkage, and gear assemblies
Conforms to NAS (National Aerospace Standard) specification
Replaceable maintenance fastener in certified aircraft structures
Requires properly reamed hole for correct interference fit