The Rotur Set of 5 Locking Nuts is a must-have accessory for pen turning enthusiasts. Made in the UK, these high-quality locking nuts are designed to provide maximum stability and security when turning pens. Each nut has a thread size of 1/4" BSF, making them compatible with the Pen mandrel shaft, brass nuts, and other standard pen mandrel accessories. The set includes five locking nuts, ensuring that you have plenty of spares for your pen turning projects. These nuts are easy to use and durable, providing a reliable solution for securing your pen blank in place while you turn it. 5 Locking nuts: PM5N