What Is a TCT Hole Saw and How to Use It
The definition of a TCT cup mill is simple: an indispensable tool for drilling metal with large diameters. And, above all, for working on particularly hard elements. It's no coincidence that the acronym TCT stands for Tungsten Carbide Tipped.
That is, tungsten carbide tip, one of the most efficient materials for working on surfaces that don't drill easily. All this is useful for introducing a crucial topic: discovering how to use your best TCT cup mill. But let's start with the basics, let's first try to understand what it is and how we can choose it. Then we'll explore the techniques for drilling metal.
What is a TCT cup mill, definition
With this term - TCT cup mill - we mean a drill bit suitable for hard metal surfaces. It has a larger diameter than what you get with any ordinary bit. We can say that there are different models of cup mills.
Some models have a diamond-tipped edge, these are those designed for drilling porcelain stoneware and tiles; other solutions, on the other hand, feature the classic teeth for cutting soft materials such as wood or plastic. Not to mention drywall.
TCT cup mills have another essential feature for workshop work: they are perfect for steel. They feature teeth made of hard metal and have the opportunity to drill thick sheets, tubes, and steel plates without damaging the surfaces.
What can you drill with this sleeve?
Much depends on the composition of the mill and its quality. In general, models with tungsten carbide teeth can easily operate on all hard metals such as stainless steel, iron, copper, cast iron, brass, and bronze.
The key characteristic of a TCT cup mill is precisely the composition of the teeth. Tungsten carbide is a much more resistant and efficient metal than HSS steel which is the basis of most quality drill bits.
In its pure form, tungsten carbide is unsuitable for application on cutting tools. So it is combined with other elements: this results in a ceramic-metal material known as cemented carbide or widia (from the German "wie Diamant", like diamond).
How is a TCT cup mill made
The structure of a cup mill for drilling hard material you recognize immediately. There is a shank for connecting the tip to the chuck, a metal sleeve usually made of special steel and teeth made of tungsten carbide designed for machining and cutting the most difficult metal surfaces. In the center we have a point for centering the hole and maintaining stability in the machining.
Here at the top we have an example of a TCT cup mill from Krino with all the features listed. Often, as in this case, you can notice a spring around this central element: it serves to automatically eject the cutting debris after cutting. This solution is fundamental for speeding up the work and avoiding having to use other tools after the drilling phase.
The profile of the teeth varies depending on the model and brand, each brand proposes its best solution based on tests and results obtained from field trials. Usually the best models feature a three-sided shank to prevent slipping of the shaft.
How to use a TCT cup mill
The best solution to exploit the potential of the TCT cup mill: drill a piece of steel, a sheet or a tube. To best use this cutting tool you simply need to mount it on the drill, choose the rotary motion, and direct the centering point to where a hole needs to be drilled. What to do when you work on tubes with a smooth and round surface?
It's best to use a center punch to create a small depression that acts as a marker. This way you avoid the mill slipping. Proceed at medium speed and lubricate to simplify the job and ensure greater longevity of the tip. The spring allows you to push out the cutting debris easily. Once you've finished the job, clean and store the mill in its case.
Which mill should I buy?
When working on hard materials like stainless steel and high-alloy solutions you need to use cutting tools of impeccable quality. Following this line we developed the cup mill with hard metal teeth TCT lite Krino. Our product is designed to drill tubes, profiles and sheets with maximum possible precision because it features a profile with double sharpening.
This makes the Krino cup mill a maximum cutting depth of 25 millimeters, it allows holes on materials with a thickness of up to 5 mm. So it is extremely valid on resistant materials like steels with R ≤ 1300 N/mm2.
Another interesting aspect of this model is the unique design with three anti-slip profile shank that guarantees maximum grip of the chuck on the shank: all this brings further precision in the work and reduced vibrations during use on the drill.
