JRP Riveting Products M6x23.5 (1.5-4.0) Steel Countersunk Head Round Knurled Body Closed JRP Rivet Nuts (Box of 300)The JRP Riveting Products M6x23. 5 Steel Countersunk Head Round Knurled Body Closed Rivet Nuts are designed for secure fastening in various applications. These rivet nuts provide a strong hold and are easy to install, making them ideal for both DIY and professional projects. High Quality Steel Construction for Durability Knurled Body for Enhanced Grip and Stability Closed Design Prevents Debris Ingress Compatible with M6 Threads for Versatile Use Easy