General information on steel beams
Depending on their shape, steel beams are called I beams, H beams, T beams, double T beams, U beams or angle beams and are mainly used in building construction. The flange thickness and the web can have different dimensions depending on the steel beam (e.g. H-beam).
In our article High Speed Steel: From which steel are drills made of we have already looked at the various applications of steels.
Steels are generally divided into construction and tool steels based on their use. Tool steels are used for the production of drills and structural steels for the steel beam.
Structural steels can have different tensile strengths which are given in N/mm². The lower the tensile strength, the softer the steel. Usual tensile strengths for structural steels are less than 500 N/mm². With high-speed steel (HSS) drills, you can usually machine steel up to 900 N/mm².
With which drill can I drill in steel beams?
As mentioned above, you can use high-speed steel (HSS) drills. Typical drilling is with an twist drill, core drill or hole saw, in the tool steels HSS, HSS-Co 5 and tungsten carbide. Hole saws can also be used as they do not drill fully into the workpiece like core drills.
Since relatively large holes often have to be drilled in steel beams for screw connections, holes are drilled with core drills or hole saws. With large diameters, you have the advantage that it does not drill into the full surface and therefore requires less time.
If you have neither a core drill nor a hole saw at hand, you can also use a twist drill.
For holes with a diameter of 6 mm or more, you should definitely pre-drill with one (or more) smaller diameters when using twist drills.
With a diameter of e.g. 16 mm you should pre-drill at least twice. Drilling with a twist drill will take much longer and is not very efficient.
As an alternative to core drills, hole saws or twist drills, you can use our ULTIMATECUT step drill.
Usually, stepped drills are used to drill into sheet metal up to approx. 4 mm. The special feature of the ULTIMATECUT step drill is the step length of 10 mm each. This allows you to drill HEA and HEM structural steel. Several diameters are also available in one drilling prozess.
Compared to the twist drill, pre-drilling is not necessary because of its steps. This means that no tool changes are necessary and you achieve time savings of up to 75% with larger diameters.
In contrast to core drills, the ULTIMATECUT step drill can be used in a hand drill and is therefore completely flexible when drilling. This also applies to hard-to-reach areas that you would otherwise not be able to reach with a core drill.
If you have to drill several holes of different sizes into the steel beam, tool changes are not necessary. You can leave the step drill inserted and go straight to the next spot that you want to drill. This saves you a lot of time.
There is also the possibility to deburr the hole with the step drill.
What do I have to consider when drilling into steel beams?
1. Statics (load-bearing function)
The statics should not be affected by your drilled holes. You should also consider whether the steel beams have a load-bearing or non-load-bearing function. If you have to drill a lot of holes, it is better to have a structural engineer come who can give you the go-ahead. Safety first.
2. Note which steel the beam is made of
Depending on which steel the steel beam is made of, you can use a twist drill (min. HSS-Co 5, better tungsten carbide) made of conventional structural steel, if it is made of stainless steel use an HSS-Co 5.
Temperatures of up to 600 °C occur during cutting. In order to extend the service life of your tool, you should always use coolant when drilling into steel beams.
When drilling with a core drill, it is essential to adjust the speed and feed rate depending on the drill.
5. No gloves
You should not wear gloves, because they can get caught in the drill.
6. Potective goggles
In contrast to the gloves, you should use protective goggles.
Conclusion and summary
The following drills are basically available for drilling into a steel beam:
In order to know which drill you need, you still have to ask yourself a few questions:
- What diameter will the hole have?
Holes up to 6 mm can be drilled with a twist drill. Diameters more than from 6 mm use core drills, hole saws or our ULTIMATECUT step drill. If you want to continue drilling with a twist drill, you should definitely pre-drill with a smaller diameter.
- How many holes do I have to drill?
For example, if you have ten holes with different diameters to drill, it would make sense to use our ULTIMATECUT step drill. If the diameter remains the same but you only have two holes, then use a core drill or a hole saw. You would only use a twist drill here if you have few drill holes and a diameter smaller than 6 mm, because you would have too many tool changes and would need too much time for pre-drilling. Also note that drilling into the full material takes more time.
- Is the spot to be drilled easy to reach?
For drilling, e.g. with a core drill for large diameters, a Core drilling machines are used. With it you are rather less flexible and you can't get to hard-to-reach places. The situation is different, for example, with hand drills in which you can clamp the ULTIMATECUT step drill.
- How thick is the flange or web you want to drill?
With a thickness of up to 10 mm and e.g. a diameter of 14 mm you can use our ULTIMATECUT step drill. If the thickness is more than 10 mm, use core drills or hole saws.
- Which steel is the steel beam made of?
Usually, steel girders are made of conventional structural steel and have a tensile strength of less than 500 N/mm². So use high speed steel (HSS) drills because they cut steel with tensile strengths up to 900 N/mm². In rare cases you will come across a stainless steel beam. If this should happen, use a HSS-Co 5 (HSS with 5% cobalt) twist drill, hole saw, HSS-Co 5 core drill or core drill with hard metal blades.
Once you have answered these questions, you know which drill is right for your application.
Note also when drilling
- to the statics (the steel beam has a supporting function)
- which steel the beam is made of,
- that you are cooling,
- that you adjust the speed,
- that you are not wearing protective gloves and
- that you put on protective goggles.
Now you can select the right drill and drill into a steel beam.
If you have questions, please do not hesitate to contact us.