Shoulder bolts are similar to a socket bolt with a standard hex head but with an unthreaded section known as the shoulder across the middle of the shaft of the bolt. This smooth section of the shaft allows the bolt to pass through a piece or pieces of material and act as a pivot point. The bolts shoulder has a larger diameter than the thread so the thread can fit through the material easily for fastening. Available in a range of sizes both metric and imperial, shoulder bolts are typically made of steel and often feature a straight knurling around the bolt head.Where can I use a shoulder bolt?Used in a range of applications from household products through to aerospace. The shoulder bolt can be used in both a manual and a mechanical application and work as a linear slide. The ability to accurately align tools such as dies and moulds while providing a robust point of contact can make a shoulder bolt invaluable.