Hardly any book is opened as often in metalwork training as the technical handbook. At the same time, your phone is almost always within reach. Is a technical handbook worth having as an app – and what does it need to do to really help in the workshop?
Which pages you really need
A printed technical handbook has several hundred pages: maths and physics, materials, standard parts, drawing, manufacturing processes, control technology. In everyday work, though, it usually comes down to a handful of questions:
- What are the limits of size for this fit?
- Which drill do I use for the tap drill hole?
- What spindle speed and feed do I set?
- What torque do I tighten the bolt to?
- What deviation is allowed on a dimension without a tolerance?
These are exactly the questions you leaf through the book for – and then often carry on working them out on a calculator.
Where the book is strong
The printed technical handbook has real advantages. It needs no battery and no signal. You see many values at a glance and recognise relationships, such as how the tolerance grows with the diameter. And above all, in many exams it is the aid you work with.
Where an app can do more
A good app is not a photographed book. Its advantage is that it calculates for your specific case:
- Calculate values instead of reading them off. A table only shows the values someone wrote into it. A thread with an unusual pitch, a diameter between two rows or a bend radius that is not in the list – an app calculates them just like the standard cases.
- Fewer reading errors. Wrong row, wrong nominal size range, a sign overlooked – this happens quickly, especially under time pressure. If you enter the nominal size and tolerance class, you get the limits of size directly.
- The calculation steps become visible. If the app shows how it arrives at the result, you learn the formula along the way. For apprentices, that matters more than any ready-made number.
- The sketch matches the case. Instead of a generic illustration, you see your tolerance zone, your thread profile or your bolt circle.
- Always with you. At the machine, on site or in the stores, your phone is usually closer than the book in your locker.
What to look for in a technical handbook app
| Criterion | Why it matters |
|---|---|
| Works without internet | Reception is often poor in workshops and basements. |
| Shows the calculation steps | Only then can you check and understand the result. |
| Marks guide values | Cutting data or bending forces are empirical values, not standard values. That has to be clear. |
| Calculates in every direction | Sometimes you need the spindle speed, sometimes the cutting speed from an existing spindle speed. |
| Quick input | At the machine, few taps, large fields and clear units are what count. |
| No account, no ads | A tool should do its job, not collect data or distract you. |
And in the exam?
There is a clear rule here: in intermediate and final exams, smartphones are as a rule not allowed. The examining body decides which aids are permitted, and that is usually the printed technical handbook with a non-programmable calculator. If you are preparing for the exam, you should therefore also practise with the book and know where each table is.
An app is still useful for this: for checking practice exercises, for understanding the calculation steps and for checking your own solution.
Conclusion
Book and app are not mutually exclusive. The book gives you the overview and is the standard in the exam. The app calculates your specific case in everyday work, shows you how to get there and fits in your pocket. That is exactly what Gesello is made for: a technical handbook that does the maths.