Choosing the right drill for your flexible shaft & drain cleaning chains

Choosing the correct cordless drill for using your flexible shaft & cleaning chains is one of the most asked questions we receive from our customers. We'll do our very best to give you an informed answer in this article.

There are few variables in using a combination of a work-ready flexible shaft, cleaning chains, descaling chains, brushes and other tools for clearing and cleaning sewers & drains.

The first factor to consider is the size of the shaft you'll be running. The most common shaft sizes in the market today are 6mm, 8mm, 10mm and 12mm. Choosing the correct shaft size for the task at hand varies by the job you need it to complete. If you're working in confined pipe sizes such as DN50 (2"), you don't really want to have a 12mm (1/2") shaft as the pipe is going to get really crowded, really fast.

So optimally you'll choose your cable according to:

- The lengths at which you'll be working with

- The force you need to accomplish the cleaning job

- The total size of equipment suitable for the pipe you'll be working inside of

- The task you need to accomplish

- The power of equipment you'll have to use the flexible shaft with tools; in this case, your cordless drill.

If you're just doing a light cleaning job inside a relatively fresh PVC pipe, you're solid by going in with a smaller shaft (8mm, even 6mm), and with just light brushes or light cleaning chains without carbide tips.

If you're going to clean a DN100 (4") pipe with some heavy, rusty scale formed inside, you'll want to move up to at least 8mm, even 10 or 12mm if you're working at lengths beyond 15 meters (50 ft) as you'll be using heavy tools like cleaning chains with carbide tips brazed on it. You'll want your shaft to be able to handle the torque presented by the scale you're about to remove.

And in order to provide the torque you'll need for these specific jobs, you'll need to have a suitable cordless drill for operating the shaft - given that you wish to use a cordless drill. In this case cordless is what we are looking at.

The raw technical specifications that we'll need for working with the flexible shafts are torque and speed in RPM.

While you might be able to handle your smaller shafts with a less powerful drill, when ever you go beyond 10 meters (33 ft) in basically any shaft size, you'll want to make sure you have enough torque available in your drill. Typically, 80 Nm or more is sufficient amount, but generally... The more, the better.

You'll also want to have enough speed available, so that you won't end up just "slapping" your chains against the pipe - you'll need around 1400-1500 rpm minimum to make sure the cleaning chains, both standard 1, 2 and 3 chained cleaning chains and the circular chains which operate based on centrifugal force distribution, run as they are designed to.

While most drills have the 1400-1500rpms available on paper, you should always take into consideration that the RPM's might be different when they reach the end of your shaft, and the cleaning chain. The longer the shaft, the more power it consumes on the way from the rotator drive shaft to the cleaning chain.

Keeping this in mind, our suggestion is to go with a drill which offers you at least 1900 RPM's, preferrably even more.

One other extremely important thing to consider when using a cordless drill to rotate your flexible shafts is safety.

There are various dangers when cleaning a pipe with a flexible shaft and a cleaning chain, out of which one of the biggest ones is running your tool / shaft stuck inside the pipe while rotating the drill.

If you don't have sufficient safety equipment in place, this presents a high risk of injury to the drill operators wrists.

In order to safeguard yourself from this, you should always use a cordless drill that is equipped with an automatic torque control system which, if the drill runs stuck, cuts the power and provides safety to the drill operator.

Our suggestions for a drill for your flexible shaft as of late 2024 are:

1. Hilti 10W-A22 Cordless Drill with the ATC Safety System (120Nm / 2100 RPM)
2. Makita XGT® 40V MAX Cordless Drill with the AFT Safety System (140Nm / 2600 RPM)
3. Milwaukee M18 FDD3 Cordless Drill with the AutoStop Safety System (158Nm / 2100 RPM)

You can also use a corded drill. This is common especially with thicker and longer shafts. One of the most commonly used corded drills for this application is the Bosch GSB 21-2 RCT.

*** Please take note that this is not an official safety guide or safety guidance, and that you are operating the flexible shaft at your own risk ***

That's all for now - if you have any questions regarding choosing the right tool for running your cleaning cables & flexible shafts, please reach out to us. We're here to help you out with what ever professional advice you might need regarding your drain cleaning, pipelining, connection lining & pipe patching business!