Hillman Round Head Machine Screw, 8-32 x 1-1/4 In. Machine screws are designed to fasten metal parts together either by using nuts or by screwing directly into a threaded receptacle. The length of the screw is measured from the underside of the head to the tip, ensuring precise fit for your fastening needs. For optimal performance, it is to pair these screws with nuts that have the same finish and threading, providing a secure and reliable connection. Model Number: