The R5 series uses a factor of 1.58 and contains the following sizes: M2.5, M4, M6, M10, M16 and M24 When you are done drilling a single hole, move on to testing by using a ⅜” tap. It will give you a practical comparison, and it will be apparent if you are headed on the right path.

Say, for example, a typical 29-piece set. In the following drill bit chart are the typical fractional sizes this kind of set would include. Letter gauge drill sizes are used primarily in North American with A starting with the smallest size working 26 size increments to Z. Gauge A tap drill size is the diameter of the hole that needs to be drilled before a threading tap can be inserted. It is important to use the correct size drill bit, because if the hole is too small then the tap will not fit properly and if the hole is too large then the threads will not be deep enough. The 3/8 tap drill size is a common size because it can be used for a variety of different applications.Titanium-Coated: These pricier drill bits don’t create as much friction as steel, so they reduce the heat produced while you work. They’ll effectively drill through most woods, fiberglass, soft metals, and PVC or similar plastics. We like the Bosch Titanium Metal Drill Bit Set because it's suitable for most materials and comes with a convenient carrying case. We’ve partnered with JustAnswer Home Improvement to help connect people like you directly to experts in home projects, tools and building materials (yes, even drill bit questions!). Keep in mind that it is always better to err on the side of too large a hole rather than too small, as a small hole can cause the tap to break or skip. With the right drill bit, a 3/8 tap will create threads that are strong and durable. Conclusion This is especially useful when creating a hole from the outside of your house to the interior. Lengths of up to 18″ or more may be needed.

If you have this set, or need to match, just use a simple formula to convert from metric to fractional inches, and vice versa: Keep an eye on your drill bit, and it should not get too hot. Do not forget to sharpen the drill bit and use cutting fluid. Number and letter sizes are commonly used for twist drill bits rather than other drill forms, as the range encompasses the sizes for which twist drill bits are most often used.Although the price tag is a bit more than other options, we think it's a great value, considering the quality and durability of this set. You'll be using these bits for a long time. Draw a mark where you want to drill and wear your safety goggles and gloves. It is advised to mask the area with painter’s tape to keep the drill bit in one place. I personally use JustAnswer, and they’ve gotten me out of a bind more than once. I can’t tell you how much time and money they’ve saved me. For example, something just above 31/64″ would be a half-inch, and anything above 63/64″ would be a 1-inch drill bit size. Sets with even more varying drill bit sizes would include diameters smaller than 1/16″ or larger than 1-1/2″.

If you need drill bit sizes that are larger than 1″, you can often use a spade bit for wood and other soft materials. It’s also helpful to find the substitute bit size to cross over between metric and standard measurements. How to Convert and Find Equivalent Bit Sizes You can use the drill chart that follows this section to help convert sizes, or you can do the math yourself.Metric dimensioning is routinely used for drill bits of all types, although the details of BS 328 apply only to twist drill bits. For example, a set of Forstner bits may contain 10, 15, 20, 25 and 30mm diameter cutters.