Hi Zen,

```
I guess I was hoping for some rules of thumb about what size of
round wire to start with to end up with a particular size in the
half round or square wire that you're drawing. I'm sort of limited,
budget wise, and I can't really afford to buy each and every gauge
of Argentium sterling and experiment if there's the possibility of
narrowing my choices down to fewer sizes.
```

Here’s where you high school geometry class will come in handy.

To see what size round wire it takes to make a given size of 1/2

round calculate the diameter of the 1/2 round. (It helps to have a

calculator with a ‘pi’ key on it.)

The dimension of the flat side of 1/2 round wire is listed as the

same dimension as the diameter of round wire e.g. 16 ga round is

.051" in diameter, 16 ga 1/2 round is .051 across the flat. A line

from any point on the outer edge to the center point of the flat

side is .0255".

To find the area of 16 ga 1/2 round, find the area of a 16 ga round

wire, then divide that number by 2 for 1/2 the area.

Area = pi r squared (r = radius of the circle (wire))

A = pi (3.14) x .0255 squared (.0255 x .0255=.00065025) =

.002042821 sq. in.

16 ga round wire has a cross sectional area of .002042821 sq. in.

16 ga 1/2 round has a cross sectional area of .002042821 sq. in.

divided by 2 = .0010214105 sq. in (round to .001021410).

Now it’s necessary to see what size round wire has a cross sectional

are of .001021410 sq. in.

To do this the same formulae are used.

A = pi r squared (r = radius )

.0010214105 sq. in = 3.14 x r squared

Since we already have the Area, we need to divide the area by pi

(.001021410 sq. in divided by 3.14 = .000325125)

r squared = .000325125

r = square root of .000325125 = .01803122 inches

diameter = 2r ( 2 x. .01803122 inches) = .03606244 inches

Now it’s a matter of looking at the wire gauge or a table of wire

gauge dimensions & finding a wire that has a diameter of .03606244

inches or a little more. In this case, 18 ga which has a diameter of

.040".

Soldering about 25 to 35 mm (1 -1 12/") of the end of 2, 18 ga

round wires together & drawing them through a drawplate with round

holes will provide 2, 16 ga 1/2 round wires.

Using 2, 18 ga round wires drawn into 2, 16 ga 1/2 round wire will

result in the 1/2 round wires being approximately 23% longer than

the 18 ga wires drawn.

This can be found by dividing the area of the larger (18 round)

diameter wire by the area of the smaller (16 1/2 round).

area of 18 ga round .040 (diameter of 18 ga) divide by 2 = .020

(radius of 18 ga) A = pi x r squared (3.14 x .0004) = .001256637

sq. in.

.001256637 divide by .001021410 = 1.230296415

This same methodology can be applied when converting any shape &

size wire to any other shape & size. Just use the mathematical

formulae for calculating the area of geometric shape of a cross

section of the wire.

Additionally, it can be used to determine how much of a larger wire

to draw to produce a given length of smaller diameter wire.

Dave