Torsion Test in Copper Rod 8mm

I want to know
Are there any Standards to define the Torsion Test ( 25RTF & 14RTF ) for Copper Rod (8mm). What Is the difference when changing the Gauge Length of Torsion Tester?

Regards,
BalaGanesh.S.

Hello,

Unfortunately I do not have access to my reference books at the moment so I cannot tell you more about the Standard. Hopefully there are others that can assist you in this regard.

Changing the length of the sample under test should have an effect. I should imagine that, as the distance decreases, the severity of the test increases.

There have already been discussions regarding torsion testing copper rod.

kishor: 07-21-2009 www.wirenet.org/forum/viewmessages.cfm?Forum=12&Topic=720
copper: 08-05-2009 www.wirenet.org/forum/viewmessages.cfm?Forum=12&Topic=732

It is interesting to note however that you are all from the same small country and likely the same plant. Are you just one person, logging in under different names?

Regards
Peter J. Stewart-Hay
Principal
Stewart-Hay Associates
www.Stewart-Hay.com
519 641-3212

Since after every discussion this topic is coming up about country and plant, I would like to clarify that although a small country two continous copper casting plants are in operation from last more than one year. Both are from different manufacturer and third plant will be operational within next three months and also from third manufacturer.
So definately it is not the same person and same plant.

Oops!

Thank you very much for the information kishor. I was aware of the new plant but certainly was not aware that there are two continuous copper casting plants in your country, let alone three.

I stand corrected.

Thank you again.

Regards
Peter J. Stewart-Hay
Principal
Stewart-Hay Associates
www.Stewart-Hay.com
519 641-3212

Hello baji1985

I recommend you to read (as it was several time mentioned previously on this forum)to read Robert L.Hamill and Sharon K.Young work "A new concept in the evaluation of the 10x10 twist test for copper rod".
It's very interesting and you have all the required information that you need regarding the twist test.

Dear Bala Ganesh,

I wonder if 8mm rod you are dealing with is "as cast" structure (direct casting to 8mm, without hot rolling).

If so, there is not any standard for torsion test.

However there is an AD HOC torsion test I developed together with some colleagues almost 15 years ago (and it has shown its usefulness since).

Length of sample 250mm (free space between grips), one fixed grip (I mean completely fixed, not the sliding type used for ETP torsion tests). The turning grip should not go faster than 30 rpm.

You let the system work in one direction until the rod breaks.

Any rod with 45 or more turns to break will be good for normal gauge wires (let's say up to 0.2mm). Above 50 TTB the rod will be OK for micron sizes (experienced only up to 40microns).

Note: a break at the grip invalidates the test.