Hillman Round Head Machine Screw, 1/4 x 2-1/2 In. are designed to securely fasten metal parts together, either by using nuts or by screwing directly into a threaded receptacle. These machine screws are measured from the underside of the head to the tip to determine the exact length, ensuring a precise fit for your fastening needs. For optimal performance, it is to pair these screws with nuts that match in finish and threading. Model Number: