1/2" (3/8) x 2" 1/4 BSF Shoulder Socket Screws, Self Colour (BS2470)

A shoulder screw has a partially smooth shaft that will allow the bolted material some rotation and movement around the screw axis, while the threaded end will typically have a nut to maintain the screw's position. They are used in instances where pre-tapped holes require alignment with some tolerance. This allows the work pieces either a joint, pivot, or sliding motion.