What Size Drill Bit For Ethernet Cable?

If you are looking to run some ethernet cable through a wall then you may well be wondering what drill bit you need. Well, let’s have a look and find out!

Terminated Or Un-terminated

This is the main question that will decide how large your hole needs to be and therefore the size of your drill bit. Is the ethernet cable terminated or un-terminated?

If you are looking at me like I’m speaking in tounges then don’t panic, all this means is does it have a plug on the end of the cable or not?

If your cable doesn’t have a plug on the end then the hole you will need to drill will be much smaller. If you are not sure what I mean by plug then it is the little plastic bit that plugs into your router or PC.

Un-Terminated Cable

This is definitely the easier and the neater way of feeding an ethernet cable through a wall. You will obviously need to drill a much smaller hole if it doesn’t have the large plastic head on the end of the cable.

How does this work though? How do you connect the cable back up?

It is actually very simple to terminate an ethernet cable, you just need the right tool and also need to find a wiring diagram online. This is because the coloured wires have to go in a certain order.

Everything you need is in the kit above, it even comes with a tester to make sure you have wired everything up correctly.

You just insert all of the cables into the plastic terminator and then crimp it down using the tool and you are done.

Drill Bits For Interior Walls

If you are running the cable through a wall without a plug on the end then you need a 6mm bit. What exact bit you need will depend on whether you are going through an interior or exterior wall.

If going through an interior wall then I recommend one of these Bosch multi-material bits, I use these every day and they are great and go through all kinds of materials so it doesn’t matter if your wall is brick, plasterboard or even wood this bit will work.

I have gone for the 150mm drill bit here which is quite long but should be enough length to get you through the vast majority of interior walls in the UK.

If your cable is terminated and you don’t want to chop it down and re-terminate it yourself then you will need to drill a much larger hole.

Remember it doesn’t need to just be big enough for the plug to fit through but you also need some wiggle room so that you can get the cable through. That rectangular plastic end is just asking to get stuck as you try and force it through the wall.

I would recommend a 16mm drill bit to give you the room to fit everything through. This one above from Bosch has a step-down chuck so that it will fit in most DIY’ers drills.

Be aware with other drill bits this large that the chuck is often too wide to fit in a lot of drills, so just watch out for that if you choose to buy another bit.

Drill Bits For Exterior Walls

If you want to route your cable outside through your wall then you will need a really long drill bit. Just let me say that I don’t recommend doing this and would strongly advise you to find an interior route instead.

The reasons for this are multiple but the main one is you can do a lot of damage. You can make a mess of your interior brick but this could be the least of your issues.

You will be bridging the cavity between your walls in most houses, if you end up with a leak from the exterior then it can follow the cable through past your cavity and into your home.

This could cause lots of mould issues inside your cavity that can be very expensive to fix.

In newer homes, you will also be penetrating your vapour barrier which again, if not sealed properly can have dire consequences.

It’s quite a large risk just to run an ethernet cable, and if you are running it outside to come back in again upstairs for example then you will be drilling two holes and doubling your risk.

A 16mm drill bit should do the job if you do want to go through with this, but it will need to be long. This 400mm bit should give you the length you need.

An Alternative Idea

What I would do, and often have, is run a thin ethernet cable and run it under doors and along skirting so you don’t need to do any drilling.

These low-profile ethernet cables can fit under doors and under the carpet and are quite hidden even when running along the top of skirting board.

They are a much easier way of running cables than drilling through your walls!