Length of 250g of 37 SWG (40 AWG) wire?

What is the approximate length of 250g of 37 SWG (40 AWG or 0.17mm
diameter) enamelled copper wire?

Where can I see a chart showing this sort of info for other gauges of
enamelled copper wire?

 

It's just possible a manufacturer may have date, like these people:
http://mdmetric.com/tech/wirewt.htm

 

or http://www.interfacebus.com/Copper_Wire_AWG_SIze.html

 

You did say "enamelled" so I ass-ume you mean magnet wire:
http://www.mwswire.com/tech_book.htm

 

Density of copper = 8.94 gm/cm3 (various sources give 8.92 to 8.96.)

I don't know what the weight of the enamelling is, but as copper is more
dense than iron, I'll ignore it.

250g of copper / 8.94 gm = 27.964 cm3.

Cross section area = PI * r (in cm here) squared = 0.00022698 cm2.

Length is 27.964/0.00022698, so 123200 cm.


You might have to take the weight of the enamel into account with that thin
wire, but I think a calculation might get close enough.

 

My wire tables say AWG 40 is 33,410 ft/lb.

So, for 250g =0.551155655 lb would be 18,414 ft = 5,600m, about 4.6x
as long.

The reason for the discrepancy-- the diameter of AWG 40 is given as
3.145 mils or about 0.08mm. Square the ratio and we have the
difference accounted for.


Best regards,
Spehro Pefhany

 

Or, to put it another way, how long is a piece of metal string? >

What with the differing vlues for density, the unknown thickness and weight
of enamelling, and what may or may not be a confusion somewhere between
radius and diameter, the room for error is large. The OP gives 0.17 mm as a
diameter, but yours might be a radius, given a figure of 0.08. I've no idea
which is right, but that half/double between the two values is suggestive.

 

Apples and oranges?

Bwuahahahahah!

 

Copper wire... ALL copper wire is given as the gauge of the WIRE
part of the "wire". Not enamel or anything else.

Otherwise all current capacity declarations/calculations would be
off from maker to maker, when in fact they are merely adjusted for
factors related to insulation material and thickness and thermal
properties.

 

Bwuahahahahaha!

Basic math belongs in the basic math group.

 

So it is. I went looking. I don't know where the OP's value of 0.17 comes
from, I just took it at face value.

 

yup, but when they weigh a spool of enamelled wire the deduct the weight of
the spool and the label but not the weight of the enamel.

Bye.
Jasen