Steel Blind Rivet SB45 / MR40120; 1/4-5/16″ Grip

The Howmet MR40120 (your BR4-5SSD) is a steel steel-body blind rivet with a grip range of ¼-inch to 5⁄16-inch (0.250-0.3125 in), designed for use where only one side of the workpiece is accessible. Manufactured by Howmet / Marson, this rivet features robust holding strength and durability suitable for heavier gauge material fastening in industrial, structural, or repair settings. Body and mandrel are both steel, giving high shear and tensile capability, though corrosion protection should be considered.