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Navigating drill bit sizes can be daunting, especially when working with a 10mm tap. This article offers clear guidance on choosing the right drill bit for your task, based on my extensive DIY experience. Read on to make your next drilling project smoother and more efficient.
Contents
What Size Drill Bit for 10mm Tap?
The best overall size drill bit for a 10mm x 1.25 tap is an 11/32″ drill bit. There are variations for a 10mm tap. The 10mm x 1.0 uses a 9.1mm metric drill bit and the 10mm x 1.5 uses a 8.7mm metric drill bit.
What is a 10mm Drill Bit Converted to Inches?
A 10mm drill bit converted to inches is approximately 0.3937 inches. This conversion is based on the fact that one inch is equal to 25.4 millimeters.
| Tap Size | Metric Drill | US Drill |
| 10mm x 1.0 | 9.1 mm | |
| 10mm x 1.25 | 8.9 mm | 11/32” |
| 10mm x 1.5 | 8.7 mm |
As you can see by the chart, there are many different sizes of 10mm taps and the exact size depends on the drill bit you should use.
The metric drill measurements and the US drill measurements also matter because you might find a drill with both measurements, or you might find it with one or the other.
Having a metric tap drill chart is important because it can help you buy the right kind of fasteners for the work you are doing. The threaded percentage also needs to be considered because you need to know what drill bit size you need for the tapping application.
Some professionals use a lower percentage thread because it allows them to tap without breaking the holes. It also gives them a longer tap tool life in most cases.
If you aren’t sure what drill bit size you need or the thread percentage you need to work with, you can always ask the workers at your local home supply store and see if they can offer any advice.
How to Use 10mm Tap
One of the main reasons you need to make sure you are using the right sizes and thread percentages is because you want to make sure you are having the right size hole in the base material.
If the hole is too small, the tapping will extend too far into the center which can make it difficult to screw the bolt into the hole later on.
If the hole is too large, you will also experience problems. The bolt will not be able to meet the threads and they will not be able to stick together.
Material Hardness
However, the hardness of the material you are drilling also matters because it might affect the tap drill size. If you don’t know much about tapping drills, you are probably safe using 75%. This percentage is what can be used for most materials, especially ones that are average or soft.
If you are using a very hard material though, you will need to use 50%.
This is because they require a tighter connection with the screw and bolt. Harder materials are only things like stainless steel, steel, and iron. Most people do not use these types of materials for drilling for basic home improvement projects, which is why the most common thread percentage is 75%.
Find the best drill bit for stainless steel in my review.
If you aren’t sure of the hardness of your material or what thread percentage you need to use, I recommend asking a professional. You might also be able to ask some of the workers in the store where you are buying the materials or the drill bits as they might know what to tell you.
You can also check the manufacturer’s instructions for the drill tap you are using to see what materials it’s for. Keep in mind that even materials like aluminum and brass are considered soft materials. Some people mistakenly believe that these materials are hard, and they use the wrong size drill tap. This is why it’s important to seek advice or check the manufacturer’s details to be sure.
When to Use 10mm Tap
You can use a 10mm tap for many different home improvement projects around the house. You can change the thread percentage for different materials which makes the 10mm tap very convenient. 10mm tap sizes come in many different sizes as well and you will need to find the correct one for you before starting a project.
If you already own a 10mm tap, make sure to check the manufacture details to see the exact size you have to make sure you are getting the right drill size. The drill bit size you will use depends on the thread count as higher threads per mm or inch will mean you need a larger hole to be drilled.
Even the hole is larger though, it’s only slightly larger. It might not look much different to the naked eye, but it makes a huge difference when you are tapping and putting in the screws.
Other Considerations for 10mm Tap
Another way that you can figure out what thread percentage and tap you need to be using are by drilling through a scrap of the material you are using. This can give you an idea if you need a threaded percentage that will give you harder or softer drilling.
The whole purpose of tapping is that you want to create a threaded hole for a screw or a bolt to enter into easily. This means you need to make sure you have the screw or bolt ready to make sure you are going in the right direction as far as size goes.
You also need to make sure you are cleaning out the holes you have drilled before putting in the screw as dust and debris can make it hard for the bolt to be inserted correctly. You can blow out the dust or use a small brush to make sure you are getting out the dust. You can even use a dust collector if you have one handy.
Final Thoughts
Making the right drill bit size decision is important because you want to make sure your project can be done smoothly and correctly. The hardness of the material you are using is important because you want to make sure you have the right tools.
