Circular Connector Terminology Clarification

We often receive requests for Circular connectors, but the terminology can be confusing to those who are searching for these or their mates. I will be going through this category to help clarify some of the terminology.

Connector Type

Some of these I don’t have personal experience using, so if one doesn’t know what they look like, click the little image icon in the upper right corner of the filter. However, I do know what causes a bit of confusion: the connector types that have “Receptacle/Jack, Male Pins” and “Plug, Female Sockets” seem counter-intuitive. The best way to explain this is there is a gender description for the physical metal contacts (referred to as either male pins or female sockets) and there is a gender description for the housing that encloses the metal contacts. A Receptacle/Jack is considered a female receiving connector while a plug is considered a male counterpart that inserts into either a jack or receptacle. Plugs cannot mate to plugs (unless the connector is designed to be non-gendered) and the same happens with receptacles or jacks. Plugs mate to either jacks or receptacles (terminology/design may change per manufacturer).
To show this, here is an example:
This XLR male pin plug connector will not mate with the following connector: SC1013-ND
There are two reasons these won’t match, they are from different manufacturers and they are both plugs. The appropriate mate for the male plug looks like this: 1003-1242-ND
While the appropriate mate for the female plug looks like this: SC1014-ND

Shell Size - Insert

The shell size is supposed to physically describe what size the insert (inner part of the circular connector, minus all the plastic nuts, backshells, sealing rings, etc…) photo and part example of what an insert can look like:
The insert size can only fit so many contacts (metal pieces for making electrtical connection) in whatever designs they have avaliable. Unfortunately, insert sizes don’t necessarily follow the same standards per manufacturer. This usually requires reading the lengthy catalog datasheet each manufacturer supplies to understand some context of the numbers and/or letters the shell size calls out. Some special connectors have a call out for Millitary Specification shell sizes that are defined by Millitary standards.


This category is all about the physical orientation of the center insert and may include information about Keying (this helps mate connectors only in one direction). The most common orientations include the following:
0, 0°, N (Normal), and Keyed. The other orientations are going to be very specific to the application being used. Again, click the little image icon in the top right to compare what these look like. The catalog datasheet will also mention what orientations are available for the series being searched for.


This filter typically describes what special components are available on the connector. The variety of manufacturers that we offer sometimes have series where these features may be available as accessories (the base part will not have the features listed), while other series may not even have the feature available as accessories. Rather, they are either included in the design or not included in the design. It is recommended to look through the catalog datasheet if one wants a specific version of a circular connector or if there are available accessories to add to the connector.

One more note, make sure to check beneath the part’s attribute list to see if there are any “Mating”, “For Use With”, or “Associated” parts, this is a lot easier than looking through the giant catalog datasheets.