Understanding Gauge

 What is gauge? It is the thickness of the metal wire. Lets take a look a key rings (or o rings) to help further understand the concept of gauge.

Its easy to size out your key rings when you have them in your hand since you can tell if you like the size. However, there are several measurements you must consider before shopping online.

There are three measurements, two of which can be used to calculate the third measurement. These are:

  1. Outside diameter
  2. Inside diameter
  3. Gauge (width of the metal)

Although the picture to the left is an O ring, it will help visualize the various measurements I am referring to.

If you like mathematics then you can see that:

[outside diameter] = [inside diameter] + 2x[gauge].
Don’t forget that you have to add the gauge twice because we are measuring the diameter. (At one point I had only added it in once, causing me massive confusion.)

When I first started TS, I did not realize there was an inside and outside diameter. So, when I switched suppliers I accidentally ordered slightly larger key rings. After speaking with my supplier, I realized it was because my previous supplier spoke in regards to the outside diameter while my new supplier described items in terms of inside diameter. Most people simply speak of “diameter” so if you are looking for an exact size key ring, make sure you ask whether they are referring to the inside or outside diameter.

So now, in terms of TS key rings, here are the sizes (based on inside diameter) and finishes we provide:

  1. 21.6mm antique brass split key rings (1.7mm gauge)
  2. 24mm nickel and antique brass split key rings (2mm diameter)

If you are looking for a larger or smaller key ring, please email kam@tantalizingstitches.com . We are gradually increasing our selection and would love to hear what you are looking for.