Because you have a 12 gauge as in a talking shotgun and then you also have a 12 gauge as in a 12 gauge needle which are two completely different sizes but gauge is a unit of measurement so how does that work
In: 173
Gauge as a unit works differently in different contexts. It is, overall, a shitty unit.
In bore measurement for firearms and mostly these days shotguns, it is (and I’m serious) the number of lead spheres of that diameter that you would need to equal one pound. So, a lead ball the size of a 12ga shotgun barrel is 1/12 of a pound.
Wire gauges have a different but also convoluted standard.
Viva la millimeter/inch, down with the gauge.
With wire, it is simply how many pieces laid side by side make an inch. This also applies to needles. With shotguns, it is how many lead balls of the bore diameter it takes to make a pound. So, one is a measurement of size and the other of weight. Copied from https://www.quora.com/Why-is-the-gauge-number-of-say-wire-needles-and-shotgun-shells-inversely-proportional-to-their-sizes-For-ex-12-gauge-wire-is-thicker-than-20-gauge-wire
They’re different units of measurements. A firearm gauge is determined from the weight of a solid sphere of lead that will fit inside the barrel. So for a 10 gauge, a 1/10th lb ball fits in the gun.
For needles the number is a bit more arbitrary and is just a random measurement used by medical companies.
Gauge isnt a unit of measure at all. It is just a way to express standard units of measure i to whole numbers. For instance sheet metal thickness, a gauge 1 could be .01 inch thich, gauge 2 could be 0.2 inch thich etc. In shotgun the measurement is different as it is the bore diameter, for instance a 12 gauge is .725 inches while a 10 is a .775. basically a gauge can stand in for anything you want it to be to be easier for regular people to pick what they want as most dont want to deal with decimal points, although in metric world this isn’t of a problem as we deal mostly with whole numbers in cm or mm. The US is backwards in their eight of an inch and so on.
Gauge is a general term for measurement units. It kinda gets thrown around for things that have an actual unit of measure, but there isn’t a convenient unit of measure already around for it. Mostly for “how much of a thing we can make out of one unit of the material”.
For guns, gauge is the number of lead balls of a particular diameter it would take to equal a pound.
For needles and wire, it relates to the complicated process of making wire and drawing it out. As the metal gets stretched father, the gauge increases but the size of the wire decreases because there is less of it.
I work in the steel industry. Tubes and pipes are measured in gauges, and they represent wall thickness. Each gauge is a different thickness. There are many uses honestly
To make matters worse, only shotguns are measured by gauge. Other guns are measured by the diameter of the bore. EXCEPT, the smallest shotgun you can get is the .410. It’s measured by bore width just like all other guns. So, you can get shotguns in 10 gauge, 12, 16, 20, 28 and .410. Someone just decided to measure one differently. It’s silly.
Edit to add, handguns and rifles are measured in bore size, which is equally fucked up because some are in millimeters, like the 9mm and the 7mm and the 5.56, but some are in inches like the .22, the .38 and the .45. Come on! Standardize that shit!
Gauge isn’t a unit. It’s a description of a standard template or measuring device.
Gauges are called that because they were/are based on physical objects. In the early days of industrial automation, we used to standardize things by comparing them to a standard “gauge” to see if they fit.
An example of a gauge might be a metal block with a number of specifically sized holes in it. If a needle fits into the number 12 hole, but not the next smaller hole, then it is said to be a “12 gauge” needle.
The gauge for shotgun barrels would be a set of specifically sized rods.
It was easier in the early days of precise measurements to make a gauge very precisely once, and then always compare your products to that gauge. Now, we have sufficiently reliable measurement devices that we can measure every product if we wanted to, and making a physical gauge is no longer so necessary. There are probably factories that still use them for quality control though, just because it’s easier.
Note that this is why sometimes gauge numbering doesn’t make sense. Sometimes a smaller number means a larger size, and sometimes it means a smaller size. This is because it used to be a number written on the side of one of a set of physical objects, and what numbering system you used was basically arbitrary. Some gauge schemes have a reason, some do not.
Fraction of some larger number. Gauge is the denominator.
The bore diameter of a 12-gauge shotgun is such that a lead sphere that could fit would be 1/12 lb in weight.
With wire, and I would assume needle as well it’s a fraction of an inch.
tl;dr: it’s totally arbitrary.
The way they used to make wire was to start with a bar of metal and run it through a set of pinch rollers to make it smaller. One set of rollers can only reduce the size of the metal so much, so they run the metal through a series of rollers until it’s down to the thickness you want. The number of rollers you go through is the gauge. The more rollers, the higher the gauge, and the thinner the wire.
That’s a terrible way to measure things, especially since each manufacturer had their own rollers and so the gauge depended on the maker. Eventually a standard was defined (American Wire Guage; AWG) and you can see it on this [chart](https://www.rembar.com/resources-technical-information-on-refractory-metals/american-wire-gauge-awg/).
There are other “gauge” measurements and they’re all just as arbitrary. Examples include how far the rails on a railroad track are (4’8.5″ in the U.S. and England), or the diameter of a shotgun barrel as /u/The Jeeronian has described.
Latest Answers