Heli-Coil 4-40 UNC Hand Installation Tool Thread Inserts Tangless. This tool is perfect for any business or industrial use, providing reliable and efficient installation of thread inserts. With its easy-to-use design and high-quality materials, this tool is sure to deliver top-notch results every time. Whether you're starting a new project or looking to improve your current setup, the Heli-Coil 4-40 UNC Hand Installation Tool Thread Inserts Tangless KATO is the perfect choice.