Terminating Twin and Earth

Total volume is conserved...  I suggest that if any part of the CSA is ever 30% reduced  during pull, you are well on the way to catastrophic failure.

Oddly during this very lunch break I have had a go, only managed between 10 and 15% elongation before failure on a few samples of copper wire now in the bin, much to the amusement of others here. And forces involved were far more than normal wire stripping.

Basically I gently tension the wire and then make marks with a spirit pen on the wire as it passes marks on a reference board. Then I pull to failure, and then measure the spacing of the marks and look at the ratio. Typically marks that were 100mm apart are now 110 to 115mm apart.


Using drawing plates to reduce a wire size or to form a hex or Dflat profile, (Jewellers often do) they try to go down by less that 10% on diameter before re-annealing, as this is the onset of work hardening fractures.

M.

Total volume is conserved...  I suggest that if any part of the CSA is ever 30% reduced  during pull, you are well on the way to catastrophic failure.

Oddly during this very lunch break I have had a go, only managed between 10 and 15% elongation before failure on a few samples of copper wire now in the bin, much to the amusement of others here. And forces involved were far more than normal wire stripping.

Basically I gently tension the wire and then make marks with a spirit pen on the wire as it passes marks on a reference board. Then I pull to failure, and then measure the spacing of the marks and look at the ratio. Typically marks that were 100mm apart are now 110 to 115mm apart.


Using drawing plates to reduce a wire size or to form a hex or Dflat profile, (Jewellers often do) they try to go down by less that 10% on diameter before re-annealing, as this is the onset of work hardening fractures.

M.