Mandrel/Nosepiece Set, Compatible Tool Type Thread Setting Tool, Compatible Insert Type Rivet Nuts, Compatible Internal Thread Size 1/4 In.-20, Compatible External Thread Size 1/4 In.-20, Material Steel, Overall Length 4 in, Product Type Mandrel and Nosepiece Set, Compatible with Grainger Part Number 4BB23, Compatible with Manufacturer Model Number 4BB23, Includes -