B-6639-131 SCREW SET

The **Hartzell B-6639-131 Set Screw** (P/N **B-6639-131**) is a replacement hardware component used in applicable Hartzell aircraft propeller assemblies. Hartzell propeller maintenance documentation identifies B-6639-131 as a set screw used within applicable propeller start-lock mechanisms and related propeller assemblies. *Images are representative and may not show the exact product for sale.* --- ## Applications The **Hartzell B-6639-131 Set Screw** is used in applicable Hartzell propeller assemblies, including documented four-blade turbine propeller configurations. Always confirm the installed propeller model and required replacement part number against the applicable Hartzell maintenance or illustrated parts data before ordering. --- ## Why CJ Aerospace? CJ Aerospace supplies aircraft propellers and replacement propeller components for a range of aviation applications. Our team can assist with product information, availability and part-number identification. - 🇦🇺 **Australian-owned and operated** - 📦 **Aircraft propellers and replacement propeller parts** - 🔧 **Technical assistance with part identification and compatibility** - ✈️ **Support for aircraft owners, operators and aviation professionals** > ✉️ [Contact us at sales@cjaerospace.com.au](mailto:sales@cjaerospace.com.au) > Need help identifying the correct propeller service part? Contact our team for assistance.

- **Propeller Set Screw:** Replacement hardware for applicable Hartzell propeller assemblies - **Start-Lock Application:** Documented for use within applicable propeller start-lock mechanisms - **Propeller Service Part:** Suitable for maintenance of applicable Hartzell propeller configurations - **Hartzell Component:** Genuine Hartzell propeller replacement hardware