Screw Terminal Connector

Thread Starter


Joined Nov 1, 2008
Hi guys,

I have a PCB which has several input terminal. These terminal are basically 4mm screws which stick out (I guess you could call it male). I have a terminal head which is basically a screw hole which fits on the terminal (it would be female), and it is covered in plastic. So to connect something to the terminal what I do is stick a wire between the terminal and the head piece and then tighten it until it is secure.

What I would like to do is have a terminal head connected directly to the wire. I would like the end of the wire to be something that can screw onto the input terminal, but it would have to be two pieces. The outer piece should be able to rotate without having to rotate the entire wire so that the wire can be screwed onto the input terminal. I know I have seen connectors like this before but I forget where and I have no idea what they are called.

I would like to make the wire myself, so I just need the connector which can have a wire soldered into it in one side and a screw terminal (female) on the other.

Can someone help me out with a name of the connector or a link to a product.

Thanks a lot.


Joined Apr 20, 2004
The connector you are using is a terminal srip, sometimes called a barrier block.

There are two ways to make life easier. One is to obtain terminal loops, which crimp or solder onto the end of the wire. Some are round with a hole for the screw and an annular sleeve for the wire. Some are forked, so they can be slid onto the terminal with just loosening the captivating screw. These terminal loops come sized to the wire and the screw in the terminal strip.

The other way is to get another terminal strip with poke-in wire ports. That would allow you to just insert the bare end of the wire and tighten a clamp screw. The fum part is in determining the pitch of the terminal strip so the connections to the PCB are the same.

Thread Starter


Joined Nov 1, 2008
I tried looking at a few terminal blocks but I can't seem to find anything that will work. What I need is similar to this:

It just needs to take 4mm screws. So where the 'ID' is on the diagram, I will solder in a wire. The connector at part 'C' will screw into the screw the screw from the pcb.

Any ideas?


Joined Jan 18, 2008
If you only need a few of the connectors, you might consider making them from an acorn nut and a flat-head tubular rivet. Both are available in brass. Drill the top of the acorn nut to pass the stem of the tubular rivet. The wire could be inserted in the rivet stem and soldered. That is a lot of work to avoid using a ring or spade connector.

You may find some nuts for connecting flexible tubing and eyelets (the type that go inside the tubing to keep it from pulling out) that could substitute for the acorn nut and tubular rivet.


Thread Starter


Joined Nov 1, 2008
Thanks for the help jpanhalt and beenthere.

I don't think the rivet and nut idea will work for me, and its a lot of work anyways. Since I need a lot of these, I will probably have the part machined.

I am wondering, does anyone know how to make the kind of connector where there are screw threads on the inside, but when you rotate it, it doesn't move forward? Its like a coaxial cable. You can keep rotating the end and it won't come off, but because there are screw thread on the inside, if you put it against a screw, it will pull the entire wire forward. This is exactly what I need. Does anyone know how to do that? If anyone has some drawing (rough or CAD) that would be great too.

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