Screw the threaded end of these metric studs into a tapped hole and use the unthreaded end as a pivot point, hinge, shaft, or locator pin.

Without a head to get in the way, these screws fit in tight spaces where standard shoulder screws cannot. Either thread them in a countersunk hole for a flush mount, or install them with the shoulder sticking out to use them as pins or dowels for aligning and locating components.

Add a knob or handle to the threaded shank. A spring-loaded, nonlocking retaining ball pops out when the pin is pushed through a hole, and retracts when the pin is pulled out.