On Fri, 17 Apr 2009 04:14:40 +0100, Sandi wrote:

Some insulated multistrnd copper wire is pre-tinned and a lot is not.

What is the purpose of pre-tinned wire? As far as I can see the advantage
is that the copper core doesn't oxidise which means the wire can be
soldered or fixed to a terminate with only minimal cleaning.

Sounds like a good thing to me, so why isn't almost all wire pre- tinned?

Is cost really so different?

Does the tinning-coating replace where copper would have been in the
overall wire and tinning is of higher reistence?

Is flexibility affected?

The best I can remember was that the original plastic coating first used
when the cloth covering was abandoned was somewhat corrosive adding to the
problems of exposure to other corrosive elements including poor annealing
of the core wires and would usually result in you having to scrape the
wire ends before trying to solder them since the wire was usually oxidized
enough to interfere with proper solder adhesion off the spool new.

Tinning did away with this aggravation and the need to use corrosive flux
to get a proper solder joint. Though some of the early tinning was poor
quality and corroded also.

Early tinned wire was slightly stiffer and a tinned stranded conductor was
almost as stiff as a solid wire. with thinner plating techniques this is
not the case any more except for much of the wire made in the far east.

This was usually offset by going to a smaller gauge wire.

Most early primary electronic wiring was originally something between 14
and 16 ga. with tinned wires this became 18 to 20 ga. in most cases.

Gnack