Mittwoch, 30. Januar 2019

cable clamps - in other than intended use

Is it ok to use a cable clamp this way?
It seems to be a good solution but it is definitely "not intended use".

Clamps should be used THIS way:

As a matter of fact we have many clamps which are used this way since many years. Now I wanted to find out: What is the breaking load of a 10 mm clamp in axial load?

First a rough calculation: The steel quality should be minimum property class 5.8.

A clamp for a 10 mm cable has a bail with two M 8 screws which should be able to hold almost 2 tons each side (M8 has 19.000 N breaking load). This means: The breaking load should be minimum 3.8 tons.
Considering that the clamp will be wedged, crooked etc., still we should be in a range of more than 3 tons. Thats the theory.
That sounds a lot, considering the size of the clamp ... its so small.
I tested in this application:


And indeed, the breaking load was in all cases more than 30 kN. This was the weakest clamp (33 kN).



I tested 10 clamps:
All of them more than 3 tons.


The axial loaded applications have to hold less than 6 kN (worst case, normally max. 3 kN) In this case they would have a safety factor of 5 minimum.
Seems enough to me.