Who likes damaged screw heads? Nobody! And most certainly not me!
After slaughtered cords (see my blog about abuse of cords), I think mauled screw heads are my number one infuriation. Not only do I keep finding heads mutilated by others, even though I am very careful and do my best to use the right equipment, I damage them myself every once in a while.
Yes, it is true. I make mistakes. I screw up sometimes too. No pun intended. It used to happen more often in the past. I learned, adapted, got better stuff. So things have improved.
Mostly however I find the heads already damaged. A tech decades ago did not care about this and just fastened the screw. Screws even got tool marks during production. And of course there are sloppy collectors, clumsy tinkers and ham handed bodgers.
It drives me mad, gnarly screws. People should take more care! It looks nasty and they are often impossible to replace, as each manufacturer and every period has its slightly different head.
How mistakes were made
Basically there are two main causes for damage to the screw heads. The first main cause is deformation of the head by the application of too much force with an ill fitting tool. This happens a lot when the screwdriver blade is too narrow and too small. It can also happen when some kind of powertool or a ratchet type driver is used and the screw is over tightened.
The second main cause of damage to the head is when the tool jumps out of the slot. This nicks the head, leaving a burr. This happens when the blade of the screwdriver is too thick and does not go into the slot deep enough or when not enough downward force is applied when turning the screw.
This also occurs when a power tool or a spiral ratchet screwdriver is used and it is not properly centered in the slot. This leads to a wobble and when the rotational speeds get higher, centrifugal force makes the driver blade jump out of the slot.
You can well imagine that if a screw head gets mistreated either way, several times, it can look pretty battered.
The wrong tool, the right tool
If it was not already clear from the paragraph above, the wrong tools were used. Why? Convenience, ignorance, economic choices: during the fabrication process ratchet screwdrivers were used, techs and tinkerers alike just use whatever screwdriver is at hand instead of spending a minute to select the exact right one from a collection of a few dozen, like a proper telephone restorer. 😉
So please do not use power tools, ratchet screwdrivers, but do use the right screwdriver.
See the picture on the right, where the screwdriver is too narrow. Where the edges of the screwdriver touch the sides of the slot, there is a huge risk of deformation of the edges.
The right screwdriver is a screwdriver of the same width and breath as the slot in the screw head. The more snugly it fits, the less chance of damage to the slot.
See the picture on the left for a snug fitting screwdriver. This distributes the forces acting upon it over the whole slot, decreasing the risk of damage enormously.
It is worth while to invest a little, especially if you work in vintage telephones or other equipment, to get a variation of drivers. They do not have to be the expensive kind, as the screw heads are usually of softer metal like brass and soft steel.
Making my own
I often could not find a screwdriver that was quite right for the job at hand. Especially on European phones from the 40s and earlier brass screws were used with slots that are much thinner than they are now. That means that standard modern screwdrivers do not fit the slot very well.
Screwdrivers with a thin blade are available, but they are too narrow for the screws I want to use them on. Please mind that these screws are made of soft brass, so the risk of damage is high.
So I bought myself a nice set of vintage screwdrivers and grounded the blades to the dimensions I wanted. I am pretty pleased with those. Not only was I able to find a set of 3 very nice vintage, alsmost unused, screwdrivers, but they work very well too.
Even though we have the right tools now, and promised not to use the wrong ones, we aren’t out of the woods yet. See the next paragraph.
Use it right
Can you use a screwdriver wrong? You wouldn’t think so, but you can. After all the pics above prove it. So here is a step by step method for safely operating
- Use a screwdriver that fits well
- make sure the blade is centered in the slot
- grab it firmly and make sure you are not working at an awkward angle
- apply a gentle force downwards on the screwdriver (axial pressure)
- turn slowly, still applying gentle pressure
- if the screw does not move, slowly and gently increase the rotational force until it does
You can help save the screws!
Now you know how to treat the screws correctly. Perhaps you learned this from this article, perhaps you knew already. In any case, please practice the above! If not for esthetic reasons, then at least for practical reasons: please be careful with those heads. When the damage get too great, you will not able to undo the screw anymore.
Did you find this article useful? Or do you have any tips or methods to add? Please leave a comment below.[:]
Very usefull and well explained. Great that you share your experience Arwin and help others. Like to see more of those tips and tricks.
I appreciated this,it was my subject in secondary and higher education, General Science, now I have concentrated on searching in old electronics and old intercome PABX boxes and their phone heads. To locate the said red mercury,that’s why I’m sometimes following this programs.lastly I may like to know other old electronics contain this element, Than when succeeded I will contact you, please.
Hi Isah, please read my blog about this subject. See here:
Red mercury does not exist. It is a hoax!
Fully agree with you! I also grounded one screwdriver head to make it fit into the small brass heads. Otherwise the really get damaged easily.
Very good! 🙂