In a previous article, I told you about the tools to cut the plate, with the famous hole saw that makes it possible to make the holes of embedding for the electrical equipment (the article is to be read here).
In the case of an electrical renovation, for brick or hard material walls, it is obviously not a matter of using this hole saw, but rather a tool that resembles it: the concrete bit saw.
I will introduce you to this tool that will be essential if you are going to do electrical work in an old house, without having to repeat the dubbing.
Why use a concrete drill bit saw?
I have already answered this question in the introduction, but I may get asked this again, so I might as well do it with precision.
The concrete bit saw – also known as a concrete bell saw – is mainly used in renovation, to make the embedding holes for electrical equipment.
Its standard diameter of 2.7 inches allows, once the hole has been drilled, to seal the flush-mounted electrical box that will accommodate the socket, switch etc……
The materials concerned by the concrete drill bit:
The difference between this tool and a plate hole saw is its ability to drill through hard materials:
These are all the materials faced by an electrician on a renovation site.
Different models of concrete bit saws:
Like all tools, there are different types of them. At the end of the article, I will introduce you to the one I use.
Here is what you can buy if you need to equip yourself with a concrete drill bit saw:
The first price discount model:
It is a model often available in GSB (large DIY store).
You will notice that as a discount product, it is the price that is its first advantage (about twenty euros like this model available at Amazon).
However, be careful with the fixing system of the central concrete drill: It is a nut that locks the drill in the axis.
After a while, due to vibrations and rotation, the drill always comes loose, which requires tightening the nut. This concrete bit saw is not practical at all.
I would therefore recommend this concrete hole saw for small construction sites.
The professional model of hole saw for concrete:
For the professional line-up, let’s go directly to the model I use on site:
Focus on Fischer’s IronCut Heavy concrete bit saw:
This drill bit saw is manufactured by Fischer, a specialist in drilling and fixing tools.
It is a very robust model made of hardened steel.
Just by its weight, we quickly realize that it is a top-of-the-line model, because the material is there.
With an all-steel body, the strength of this drill bit saw is not to be proven.
The body is composed of spirals on the outside, which allows an efficient disposal of the dust generated during drilling.
The cutting depth is important since the drill bit is 4 inches long: largely sufficient since the flush-mounted boxes are 1.5 or 2 inches deep.
At the cutting part, this model is composed of 6 carbide teeth, which means that the cutting quality is good.
Use of the IronCut Heavy model:
To work with this Fischer drill bit saw, you need several references.
The 2.7 inches bit saw, length 4 inches, reference 532095.
An SDS adapter reference 532106: It allows you to attach the IronCut to a perforator.
A centering drill reference 532101: it is used to guide and orient the bit saw.
Where I remained doubtful when assembling the three references, is that there is no screwing or “clipping” to do: the elements are held together by simple friction.
It’s quite confusing at the first assembly, but we quickly understand the concept: no mechanical fixing system, therefore no wear.
Test and familiarize yourself with this concrete drill bit:
The assembly is done in SDS Plus. Below is a picture of the assembly of this drill bit on the Bosch 36V Li Plus perforator.
Be careful if the installation is done on a small perforator: the weight of the bit saw will undoubtedly cause it to tip forward.
I did a test by making a hole in a simple plastered brick wall, in order to insert an in-wall box to connect a switch.
The result is quite impressive from the point of view of execution speed, with a very good penetration into the material and an efficient dust disposal.
I liked The manufacturing quality of the bit saw. Efficient drilling in hard materials.
The depth of the saw allows you to go a little deeper to secure the flush-mounted box. I didn’t like so much: It takes 3 accessories to assemble the hole saw.