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090-00019-0007 – Textron Aviation OEM External Snap Ring
Available now through the AirParts Aero marketplace.
Overview Section
The 090-00019-0007 is a genuine Textron Aviation OEM external snap ring (also known as a circlip or retaining ring), engineered for high-reliability axial retention in Beechcraft King Air and Hawker airframes. This precision-engineered fastener is designed to be installed into a machined groove on a shaft or pin, providing a removable shoulder that secures bearings, gears, or linkages in place.
Manufactured from high-carbon spring steel and finished with a protective coating, the 090-00019-0007 is capable of withstanding significant thrust loads and centrifugal forces. As an OEM component, it meets the specific "spring rate" and material hardness requirements dictated by Textron's engineering standards to ensure it maintains its seated tension throughout the aircraft's high-vibration service life.
Enhanced Technical Data
| Technical Metric | Specification Data |
| Material Base | Carbon Spring Steel (SAE 1070-1090) |
| Hardness | 47–52 Rockwell C (HRC) |
| Type | External (Shaft-Mounted) |
| Shaft Diameter (Nominal) | 0.375 in (3/8") |
| Groove Diameter | 0.352 in ($\pm 0.002$) |
| Ring Thickness | 0.035 in ($\pm 0.001$) |
| Finish | Zinc Phosphate or Black Oxide per MIL-DTL-16232 |
| Radial Wall (Width) | 0.039 in |
| Thrust Load Capacity | 650 lbs (Safety factor of 3:1) |
Advanced Engineering & Structural Application
The 090-00019-0007 is engineered for Axial Load Retention. In aerospace applications, a snap ring must do more than just "fit"; it must maintain a constant radial tension against the bottom of the machined groove to prevent "flutter" or rotation that could lead to groove wear.
Engineering Insight: Shear and Thrust Capability
This snap ring features a "tapered section" design. The width of the ring decreases from the center toward the "lugs" (the holes for pliers). This geometry ensures that when the ring is expanded for installation, it maintains a near-perfect circular shape, allowing for maximum contact with the groove circumference. The Rockwell C 47-52 hardness ensures the ring's edges remain sharp, preventing the ring from "ramping" out of the groove under high axial thrust.
Fatigue Resistance
Unlike commercial snap rings, the 090-00019-0007 undergoes a specific isothermal heat-treat process (Austempering). This reduces the risk of hydrogen embrittlement and increases the "ductile-to-brittle" transition threshold, ensuring the ring does not snap during installation in sub-zero hangar conditions.
Aircraft Compatibility
The 090-00019-0007 is a versatile fastener found in various ATA chapters of Textron airframes:
Beechcraft King Air 90/100/200/300: Primarily used in ATA 27 (Flight Controls) for securing pulley pins and bellcrank pivots.
Hawker 400XP / 800XP: Utilized in landing gear door linkages (ATA 32) and environmental system valve actuators.
Beechcraft Baron/Bonanza: Often found in the engine control quadrant and trim tab actuator assemblies.
The Textron 090-00019-0007 is a critical safety-of-flight fastener used to ensure the security of moving linkages and rotating shafts. When maintaining a King Air or Hawker, substituting an OEM snap ring with a commercial industrial part can lead to catastrophic failure if the material hardness or spring tension does not meet Textron's exact specifications. This 090-series snap ring provides the corrosion resistance and fatigue strength required for high-utilization airframes. Ensure your flight control and landing gear assemblies are secured with the precision and reliability of genuine Textron Aviation hardware.
Installation & Maintenance Addendum
"Over-Expansion" Warning: During installation, expand the 090-00019-0007 only as far as necessary to clear the shaft. Over-expanding the ring beyond its elastic limit will cause it to lose its "set," resulting in a loose fit in the groove.
Orientation: The snap ring is manufactured via a stamping process, resulting in a "Sharp Side" and a "Rounded Side." For maximum load capacity, always install the ring with the sharp side facing away from the part being retained.
One-Time Use Policy: Per most Aircraft Maintenance Manuals (AMM), snap rings should be discarded and replaced with new units whenever they are removed, as the removal process can introduce microscopic stress fractures or permanent deformation.
