A resource correlating specific drill sizes with the appropriate tap sizes for creating threaded holes. This table presents recommended drill bit diameters for achieving optimal thread engagement when using a tap to cut internal screw threads. For instance, if a project requires a 1/4-20 thread, the reference material indicates the necessary drill size to use before tapping.
The value of this data lies in its ability to ensure properly sized holes, promoting strong and reliable threaded connections. Using the wrong drill size can lead to stripped threads, broken taps, or insufficient holding power. Historically, machinists and mechanics relied on handbooks and personal experience; this readily available format offers a convenient and accurate reference, reducing errors and saving time in manufacturing, repair, and fabrication processes.
The following sections will detail how to effectively utilize this information, explore various materials and their impact on selection, and discuss best practices for drilling and tapping to achieve superior results.
