I'm knocking up a spreadsheet to calculate cable resitance, at times one needs this stuff as brain gets older.
My old TAFE book tells me it is 1.72x10-8 Ohms per metre at 20 deg. C, and it seems to have comfirmation from Google, however I have also found a site which claims it to be 1.678x10-8 Ohms per metre at 20 deg. C but it says also for high purity stuff.
Not much of a difference but it MAY make a difference at high currents.
I have also found out that I have been robbed for years from cable manufacturers who claim that 7/0.50 cable is 1.5mm2 when it is infact 1.3744mm2 if I got my mumbers right...I'll have to sue!