Drilling Metal with Precision: Useful Techniques and Drill Bits

Drilling metal has always been an important starting point for those who do professional and hobby maintenance work. It interests those who work in construction and those who aim at DIY: everyone needs a simple and effective way to make a hole in steel, iron, brass or cast iron. But also in aluminum. However, there are conditions you need to know.

And there are tools to use. You can't simply mount a drill bit and start working: you risk getting terrible results. Here's how to drill metal with precision, trying to evaluate the characteristics of each individual activity.

Use the rotary movement of the drill

Let's start with the basics: how do you make a hole in metal? In these cases it's important to consider that the drill should have a standard setting, namely rotary. Most models - like those Total from Ineco - have two functions: rotation and percussion.

The latter is based on the ability to impart a force perpendicular through the bit (a percussion) so as to easily drill materials like stone or concrete. For metal this principle does not apply, you must use rotary motion. This is the standard motion of all drills and screwdrivers on the market, you shouldn't have any problems with this solution.

If needed, take advantage of the column's precision

How do you drill metal? It may be necessary to proceed with maximum precision. Here you take advantage of the potential of the column drill, a solution that allows you to position the plate or bracket on a flat surface and lower the bit with a perpendicular guided motion. This condition is perfect for jobs where maximum precision and consistency of motion is required.

Pay attention to good drilling practices

If you want to make a hole in metal make sure you have secured the work base well. A tube should be clamped in a hydraulic vise, with opening from above. The same goes for a plate or sheet. Also, it may be helpful to make a mark with a center punch to have both a visual element and a reference point for the drill tip: on a smooth or curved surface it's easy to slip.

Select the correct drilling speed

A larger drill bit diameter requires a lower speed. So the number of revolutions per minute is directly proportional to the hole diameter. However, when you drill a hole in metal you must also evaluate the hardness of the material you are modifying.

A standard parameter that can be observed is this: for holes smaller than 6 mm you exceed 1000 rpm (revolutions per minute), for larger ones you go beyond the indicated rpm threshold. But it's a rough definition: on fabrizio.zellini.org/velocita-trapano-metalli I found a table capable of defining with maximum precision the rpm on different metallic materials.

For large holes you must use specific bits

Remember that a hole of particular dimensions, in metal but the same goes for other materials, cannot be made with a normal twist bit: you need a cup mill. That is a kind of cylinder with sharp profile that cuts a circle in the plate. Just like our mill with hard metal teeth TCT lite from Krino, perfect for every occasion.

Lubricate the tip with the right oil

If you need to drill an aluminum plate it may be irrelevant. But if you want to make a hole in a stainless steel plate or material that is particularly thick and resistant you may want to have a good metal drilling oil available.

This product serves to lubricate and cool the tip that works through the block you are working on more easily. Another advantage: thanks to this emulsion you can keep the cutting chips in the liquid and prevent them from interfering with the machining. Practically speaking, with this solution you perform a clean and effective metal drilling operation.

Choose a bit with the right characteristics

The instrumentation for drilling metal is fundamental to getting the result you need. First of all it should have a homogeneous diameter along its entire length, a cylindrical shank and a structure made of high-speed steel (HSS - High Speed Steel).

This allows for better performance even on the hardest materials. Then those with a minimal percentage of cobalt (like 5%) are perfect for drilling stainless steel. The drilling end is slightly pointed, usually at 118 degrees angle but some models reach 135 to increase the stability of the tip when drilling harder metals.

Our solution: Step+

Do you want to choose a great bit for your metal maintenance work? The idea is to leverage all the knowledge of the Krino brand to get the best possible result. How? Thanks to the Step+ metal bit. The step geometry (ø ≥ 3 mm) offers extremely precise and circular holes. This bit is perfect for machining where excellent precision is required.

In particular, the Step+ is perfect on sheets, tubes and profiles. The stepped shape is one of the peculiarities of this product: it is 30% faster than a twist bit thanks to the particular shape of the initial part. Furthermore, the composition material - HSS AISI M2 - guarantees extra durability and versatility for drilling alloy steels with R ≤ 900 N/mm2, but also stainless steel, iron and aluminum.