Used for many years in the UK external telecoms copper network; not ideal for CAT 5 data (or CAT6,6a etc)
I believe there are similar ones for higher power applications to use instead of WAGO connectors, but are larger than shown in Vic’s video clip.

See pliers crimping 8a

https://www.britishtelephones.com/tools/plierscrimping.htm

and then follow the link to

https://www.britishtelephones.com/connectorswireinsulated.htm

Bill

Interesting, never came across them before, reminds  me of another type of wire connectors which used to be common years back, where the two wires were inserted into a cone shaped holder and simply twisted together.

And all that hand-scraping on the forest of sharp solder termimals on Main Distribution Frames… I remember Post Office Telephones issued special leather gloves to protect your hands.

Citizens of Milton Keynes had poor broadband for years as a result of these I believe. When I was with BT Research developing CATV systems for MK around 1973 they were building the city and Ali cables had just come along with these “permanent” crimps so we’re used all over.

On 9 January 2026 at 17:50 larry phelan 1 Said:

Interesting, never came across them before, reminds  me of another type of wire connectors which used to be common years back, where the two wires were inserted into a cone shaped holder and simply twisted together.

The dreaded “wire nut” “Marr connector” or “Marrette”. The early ones were just a ceramic thimble with a coarse, tapered, internal thread. Modern ones are plastic with a close wound coil spring inside. Popular in North America. Canada claims othave invented them.  Problem is poor vibration resistance. To counter this some have a brass tube with set screw, like half the inside of a “choc-bloc”, with a screw on insulation cap.
Not common in the UK and a quick  internet search didn’t find any with EU/UK approvals. This one has Canadian, CSA and USA, UL approvals :
https://tnb.ca.abb.com/en/pdf-catalogues/wire-termination/wire-connectors/833-wide-range-ergonomic-compact-design.pdf

Robert.

Wow, I still use them over here now. I also use the set screw type.

Not knowing what a wire nut was I Google it. I am glad I have never seen one.

I did meet the use of a small copper tube to join two field telephone wires while in the army cadets. We visited a signal regiment and were shown this smart idea where wire were inserted into either end of a copper tube which was then twisted. It needed three hands to do the job but was better than sitting there trying to find the one copper strand in a bundle of steel wire. With both wires prepared you had to then tie the two together. Mechanical engineering suddenly had far more appeal.

JA