1. Product Overview
The Klein Tools 66001 is a versatile 2-in-1 impact socket designed for efficiency and durability. This single-ended deep socket features hands-free adjustment between 3/4-inch and 9/16-inch hex sizes, making it ideal for various applications, particularly pole hardware installation and removal. Its high-torque, 12-point design facilitates easier positioning and compatibility with square fasteners.

Image 1.1: The Klein Tools 66001 2-in-1 Impact Socket, showcasing its compact design and size markings.
2. Safety Information
Always prioritize safety when using any tools. Adhere to the following guidelines:
- Eye Protection: Always wear approved eye protection to prevent injury from flying debris.
- Tool Compatibility: Ensure the socket is correctly matched to the impact driver and fastener size.
- Secure Grip: Maintain a firm grip on the impact driver during operation.
- Inspect Tool: Before each use, inspect the socket for any signs of wear, damage, or cracks. Do not use damaged tools.
- Proper Storage: Store the socket in a dry, secure location away from moisture and extreme temperatures.
3. Product Features
The Klein Tools 66001 Impact Socket incorporates several features designed for professional use:
- 2-in-1 Design: Integrates two coaxial spring-loaded hex socket sizes (3/4-Inch and 9/16-Inch) into a single tool for hands-free adjustment.
- Deep Socket: Provides extended reach for various applications, including pole hardware installation and removal.
- 1/2-Inch Drive: Compatible with standard 1/2-inch drive impact drivers.
- 12-Point Design: High-torque 12-point configuration allows for easier positioning and effective use with square fasteners.
- Cross Hole Design: Engineered to prevent unintentional separation of the adapter and socket, enhancing safety and reliability.
- Impact Driver Compatibility: Specifically designed for use with impact drivers, including Klein's 1/2-Inch Compact Impact Wrench (Cat Nos. BAT20-CW, BAT20-CW1).

Image 3.1: Diagram illustrating the key features of the Klein Tools 2-in-1 Impact Socket, including its dual sizes and 12-point design.
4. Operating Instructions
Follow these steps for proper operation of your Klein Tools 66001 Impact Socket:
- Select Correct Size: The socket automatically adjusts between 3/4-inch and 9/16-inch hex sizes. Simply align the appropriate end with your fastener.
- Attach to Impact Driver: Securely attach the 1/2-inch drive end of the socket to a compatible impact driver. Ensure it is fully seated and locked into place.
- Position on Fastener: Place the socket firmly onto the fastener (nut or bolt head). The 12-point design allows for easier engagement.
- Operate Impact Driver: Activate your impact driver to tighten or loosen the fastener. Apply steady pressure and maintain control of the tool.
- Pole Hardware: For pole hardware installation and removal, the deep socket design provides necessary clearance.

Image 4.1: Demonstrating the Klein Tools 66001 socket attached to an impact driver for fastener removal.

Image 4.2: The Klein Tools 66001 in use on pole hardware, highlighting its deep socket capability.
Video 4.1: An official video demonstrating the features and hands-free adjustment of Klein Tools Impact Sockets, including the 2-in-1 design for various applications.
5. Specifications
| Model Number | 66001 |
| Brand | KLEIN TOOLS |
| Socket Sizes | 3/4-Inch and 9/16-Inch Hex |
| Drive Size | 1/2-Inch |
| Point Style | 12-Point |
| Material | Alloy Steel |
| Finish Type | Brushed |
| Item Weight | 8 ounces |
| Special Features | Hands-free Adjustment, Deep Socket |
| Included Components | Impact Socket |
6. Maintenance
To ensure the longevity and optimal performance of your Klein Tools 66001 Impact Socket, follow these maintenance guidelines:
- Cleaning: After each use, wipe the socket clean of any dirt, grease, or debris. A mild solvent can be used for stubborn grime, followed by thorough drying.
- Lubrication: Periodically apply a light coat of rust-preventative oil to the socket, especially if stored in humid conditions, to prevent corrosion.
- Inspection: Regularly inspect the socket for signs of wear, such as rounded edges, cracks, or deformation. Replace the socket if any significant damage is observed.
- Storage: Store the socket in a tool box or on a tool rack to protect it from impacts and environmental damage.
7. Troubleshooting
If you encounter issues while using your Klein Tools 66001 Impact Socket, consider the following:
- Socket Not Engaging Fastener: Ensure the fastener size is either 3/4-inch or 9/16-inch hex. Verify that the socket is clean and free of obstructions.
- Socket Sticking to Fastener: This can occur due to overtightening or corrosion. Ensure proper torque is applied and keep the socket clean and lubricated.
- Socket Not Fitting Impact Driver: Confirm your impact driver has a 1/2-inch square drive. Ensure the socket's drive end is clean and free of damage.
- Excessive Wear: Using the socket with an improperly sized fastener or applying excessive force can lead to premature wear. Always use the correct size and avoid over-torquing.
8. Warranty and Support
The Klein Tools 66001 2-in-1 Impact Socket is covered by a 1 Year Manufacturer Warranty. For warranty claims, technical support, or additional product information, please contact Klein Tools directly or visit their official website.
You can find more information and contact details on the KLEIN TOOLS Store.





