How Wire Resists Bending


A question was asked in-store recently, “Is this copper wire Dead Soft, Half Hard or Full Hard?”

The difference between soft and hard are very obvious but how do you measure if something is half hard or full hard? Also why would you need to know this?

Two of the most common uses of brass and copper wire are to hang pictures and to make jewellery.

For use in hanging a picture, the weight of what you are hanging can vary and this in turn, will affect how thick or strong you need your hanging wire to be. Your frame may consist of wood and a heavy glass which would require a very strong and sturdy wire. On the other hand the frame may be a light plastic covering over the picture therefore the hanging wire required need not be so thick.

The other main use is jewellery making and this is where the terms “dead soft, half hard and full hard” are commonly used.



A metal’s hardness is a measure of how much it resists bending
.

 

Full Hard…

The term ‘Full Hard’ refers to wire that has a high resistance to bending. This type of wire is easy to break if you do try bending it but, if managed, it will hold it’s new shape. It won’t however be bent into spirals or tight bends.

Half Hard…

Wire that is ‘Half Hard’ is the middle of the scale of wire hardness. It is soft enough to bend easily without breaking but it is still hard enough to hold its shape when bent. Half Hard wire will hold a tight bend easily. Half hard wire is very malleable.

Dead Soft…

Dead Soft wire is extremely easy to bend but it will not hold it’s shape. You cannot form sharp angles with it or anything close. It offers no real resistance and, although it won’t break when bending, it can only really be used to coil round something else, for example.

 

A wires Gauge is another way to describe wire.

 

The ‘Gauge’ of the wire refers to the thickness of the wire as opposed to the hardness. It can also be described as a measurement of the cross-sectional area of a wire.

The gauge of a wire is commonly used to determine the amount of current a wire can safely handle and so these size measurements are of much more importance when using the wire for electrical purposes.

American Wire Gauge (AWG) Size Chart

The above image displays a wire gauge chart in American Wire Gauge (AWG). Another commonly used gauge chart is known as the Standard Wire Gauge (SWG). The SWG chart is used in Europe and is also referred to as the ‘Imperial Wire Gauge’ or the ‘British Standard Gauge’.

The image below compares the slight differences between the two.

Standard Wire Gauge (SWG) Size Chart

The differences are very minimal but the same sentiment exists in both, the  smaller the gauge number, the thicker the wire.

While there are set gauge measuring systems these are not the same all across the globe and in most parts of the world the diameter of the wire is still referred to in metric inches or millimeters.