Hillman Group 90413 1/4-20-Inch x 2-1/2-Inch Combo, 100-Pack Zinc Round Head Combination Machine Screw, 1/4" x 2-1/2", 100 Pieces Product Description A machine screw is a fastening screw with a machine-cut thread throughout the length of its shank. Machine screws are used with nuts or screwed directly into a threaded receptacle to fasten various components together in machines, tools, etc. Fasten with a screwdriver to reduce risk of over-tightening and protect the screw and fastened material. If nuts are needed, use with nuts of the same finish and threading for proper fit. The length of a machine screw is measured from under the head to the point of the screw. From the Manufacturer Machine screws are used with nuts or screwed directly into a threaded receptacle to fasten metal parts together. Measured from the underside of the head to the tip of the screw to obtain fastener length. If nuts are needed, use with nuts of the same finish and threading for proper fit. Features Use to fasten metal parts together Zinc finish for moderate corrosion protection Fasten with screwdriver to reduce risk of over-tightening If nuts are needed, use with nuts of the same finish and threading Stronger thread than wood screws, made finer and more precisely 100 pieces per retail package USA SHIPPING estimates delivery times and we work to get your item to you as quickly as possible and within those times, but please know it may take slightly longer than the estimate.