It fulfills the same purpose, but is essential if you are faced with guides that cover over an inch sized drill bits. If you are going through these charts you will also find Imperial Charts which allow users to compare diameters in inches instead of in millimeters. The guides are built via the correct use of taps and charts for wood screws and machine screws. Drill charts work nicely with wood and metal components. It also ensures a snug fit for treads of screws. When they twist the taps it carves out guides of the right size. After this, manufacturers then drill the hole of the right length, put the tap, and start making the guides. Drill and tap charts rely on comparing the size of a drill bit in the chart, to figure out what drill bit makes the right sized hole. This is what allows workers and homeowners to in time add the components that would complete predrilled items. Drill Size ChartĮxpert installers and manufacturers make use of the drill and tap chart to determine what taps and drills sizes to pick out for a combination that results in female screw guides. This is also because then the tap is able to make varying depths between 50 percent and 100 percent, depending entirely on how big a hole is. This helps with thread spacing, which is important in determining the right drill bit size. When you want to find the right sized drill and tap size, you also need to know if the screws that you will be using are fine or coarse. These are a bit bigger than the skinniest area of the male screw, but at the same time also smaller than the thickest area of that screw. It is true that there are tons of different ways you can make this hole but using a tap to thread the hole is the most common one.Īll standard size taps come with at least one drill bit size that corresponds to it. You will need taps for manufacturing of parts, where a hole is required to be made with a female screw thread when building and fastening. There are tap drill charts, which will give you the right tap for drilling in both measurements of millimeters and inches.

The first thing you do is consult the tap drill chart to look for the accompanying drill bit size for a tap, most of these are available online.

Tap drill chart