Yes, you can mate together the two different cable size contacts. Both male contacts and both female contacts have the same front half of the contact for mating compatibility. It is only the bore at the rear of the contact, where the wire is inserted, that is different for the 26 AWG and 28-32 AWG types. So both female contacts G125-0010005 and G125-002005 mate with both male contacts G125-1010005 and G125-1020005.

We currently recommend 3 materials that we have tried – although it’s very likely that many others are entirely suitable. Our primary recommendation, that we use on our complete cable assemblies, is Stycast 2651MM with Catalyst 9. We have also used Robnor Resins PX439XS/BK/250 and Epoxies Innovative Bonding Solutions 50-3122RBK. You can find more information on backpotting our connectors and links to the epoxy suppliers on our blog post What is Backpotting?

Once you assemble contacts into this housing, the complete connector is rated for 1,000 operations (mating and unmating cycles). This performance is shown in the C125XX Component Specification, also listed further down the page under Downloads.

The tool you need is the Z125-9261000 – this will help push in the two latch buttons when the connectors are engaged, so you can then separate the mated connectors. Consult the training video for more information on using this tool. It is also possible to push in the two buttons by hand as well, if you have good access.