MANNESMANN Torque Wrench 0-20 Nm: Locked, No Force Setting Signal, Assembly & Disassembly

Hello,
two years ago I bought a MANNESMANN torque wrench 0 - 20 Nm. I used it several times to assemble the timing. Now, after two years, I wanted to use it again and I have a problem. The key does not work. Regardless of the force setting, it is always blocked. Even when setting the lowest force during tightening, the wrench always tightens the screw without any force setting signal. I tried to undress him but first I do not know how to undress him and secondly I do not know what could go wrong, how he works.
I am asking for suggestions.
greetings

Take it to the repair combined with the calibration.
So what if you undress and repair if you do not calibrate.

Upload a photo of this key ...

I will say from experience that the calibration alone with the key for PLN 100 is not the same. The cost of calibration exceeds the cost of the key. And the cheapest keys will not pass her anyway. If someone will issue you with this certificate, know that you have been made in bambuko.

River theme. The keys from 0 to 20 nm are gone. There is always a minimum of 10% of the maximum value. Electronic down to 5%, but their price kills an ordinary mortal.

Buy something from Gedore, Stahlwille, Carolus etc. Possibly, what a pity you can do something with a factory certificate and if you search for the current certificate, the best done at the manufacturer's key because external companies can set up with an error of up to 10% despite the fact that you have a certificate with a maximum of 3%.

Thank you very much for all the information regarding my problem. At the beginning I have to apologize for the confusion that I introduced by providing the key parameters. An error crept in. I gave 10-20 Nm and it should be 10 - 210 Nm. The difference is obviously fundamental. Excuse me. But I've already got the information I need. Thanks.
I use this key only sporadically maybe once a year, that's why I bought one of the simpler and cheaper ones. I have nothing to take pictures of, so I give the link to the key I have:

www.ceneo.pl/13731717#tab=spec

I gave the key a few strokes and spoke. When it comes to calibration, I think so or can not be done in a home way. That is, connect with the ends 1/2 "two keys, this one and the other calibrated and try to bend them (as if to tighten them among themselves) and equalize their reaction (click) on the key set in a good key. What do you think. Tolerance 10 % would be enough for me.

This key is not even suitable for tightening wheels in a car. The factory is without calibration. A total toilet that is a shame for money. From what I remember it distorts about 12% and there is no repeatability of measurement at all.
So he clicks as he pleases. If you want to have peace of mind, buy something used with calibration or even even the cheapest Jonessway or Proxon, have a factory calibration with a certificate.

In general, to fumble with the car you need to have at least 2 keys. One to small moments, typical from 6 to 30 nm and the second large in the range of usually 20 - 200 nm.

Regarding calibration at home, you can donate it. You can not make a difference. Unless you have an electronic key. Clickers will click similarly, even with a difference. The key key method works only if the key is checked or does work at all, in the sense of clicking. And at what point it clicks, only the machine will check. In addition, it's about the repeatability of clicks. Norma iso to + - 4%

I see that I came across a professional. Thank you very much for such detailed information. It's good that you made me aware. And I trusted that key so much. Why bugs like this? You can make problems for someone. I think everything is for cash. This key still has the basic disadvantage. There is no lock of the set force. When you try to tighten it with screws you can not hold the handle because they change the bill.
And what do you think about swap keys, such as:


www.ceneo.pl/15656644?se=jsohTMQMtXgOBN1B1yssqcsuYNmaiX-8&gclid=EAIaIQobChMIgKCujNOO1QIVyh0YCh09NwirEAAYAiAAEgIUePD_BwE

I know it's also primitives, but maybe a little better than mine. I ask because I rarely use such a key and I can not afford something more expensive.
Greetings

If you have some practice, you will even go without a torque wrench. I use mostly for tightening pumping heads, heads, crank pins and main, otherwise rarely. You can say that I have set in the elbow, clicks on me as soon as the screw is enough

In the automotive industry, there are usually streech connections, i.e. tightening to the yield point of the bolt. Such connections are tightened in two stages - in the first stage, initially with the given force in nm, and then by an additional angle. Without a reliable pre-tightening there is a high probability of poor tightening or even breaking of the thread. So the authoritative tool is the basis here. I omit the fact of thread cleanliness, etc. Where, if the friction is greater, the key itself will click faster than it should and the tightening force will be reduced as a result.
Or when lubricating threads - larger.

None of us in NASA is working, so in most cases a good key, some knowledge and following the manufacturer's instructions is enough.

Generally about the river.


Regarding the key is probably the same as with the key Manssmann ... is cheap and nothing more. I have not met with tests of this type of keys. Probably the same as with everything ... cheaper is less calibrated than more expensive. This is always about precision and repeatability of tightening.

I assume that I am too poor to buy twice ...

And most importantly what exactly and where do you want to tighten?

I adjusted the key using the second one but the same one. Even so, I will use it only for things less demanding accuracy.
Thank you for your help.