Chicago Universal Coupling Dimensions
Chicago hose couplings are are called universal type because they connect to each other, across a range of hose sizes. A 1 inch Chicago coupling will mate with a 1/2 inch Chicago coupling. There are no male and female types, further simplifying the connection and your inventory. They also, in theory, should interchange between brands, import and domestic. Import couplings are often a little more rough around the edges but should conform to the same interchange, Unless...
There are other types of couplings less common in the USA but frequently found in European, Australian, and Asian markets. Those include a European interchange universal coupling, and Australian and Asian couplings commonly known as a Minsup or Sure-Lock, that look very similar but do not connect. If your coupling has a DIN number, British or metric thread, then it is most likely one of these non compatible types. A Chicago type Universal coupling also has a slightly different lug design, with one side being enclosed. You should be able to turn the coupling head faced down and see a backwards "J" shape.
You may be located in the US or Canada, but your equipment may have come from overseas, so you cannot be positive unless you use trial and error or measure.
Measurements of a 2-lug Chicago type Universal Coupling:
Interior dimension between the lugs: 1.625"
Inside diameter of the gasket: 0.65"
Overall height of the lugs, from coupling face: 0.625"
Overall width of coupling face: 1.60"* (This dimension does not include the extension for the pin hole, and may vary slightly due to thickness between materials and brands)
Note, 2-Lug couplings only come in pipe or hose sizes 1 inch and smaller. If you have a 2-Lug coupling that is 1.25" or larger pipe or hose size, then it may be a sandblast quick coupling or a non-compatible international coupling.
Measurements of a 4-lug Chicago type Universal Coupling:
Interior dimension between the lugs: 2.675"
Inside diameter of the gasket: 0.480"
Overall height of the lugs, from coupling face: 0.775"
Overall width of coupling face: 2.565"* (This dimension does not include the extension for the pin hole, and may vary slightly due to thickness between materials and brands)
Note, all hose or pipe sizes 1.25" to 2" are the 4-lug design, if you have a 2-lug in these sizes then it may be a sandblast quick coupling or a non-compatible international coupling.
The measurements listed here are taken from caliper readings in our warehouse and should not be considered exact. Use only to help identify the couplings that you have.
universal coupling heads are interchangeable in all 2 lug coupling sizes and in all 4 lug sizes
(but not between 2 and 4 lug couplings)
4-lug universal coupling gasket shown