Crimp pins not compatible with plug / socket combo

I recently bought some (seemingly compatible) products from Digikey but when I fit the crimp pins (A25352-ND) into the plug (A97525-ND) the plug no longer fits into is corresponding socket (A1494-ND).

Can you confirm that the crimp pins are compatible with this plug / socket combo?

Hello, Mphatak.

The combination is a valid association in Digi-Key’s systems. I’m not seeing any compatibility issues. Are you certain the contacts have been properly seated in the connector housing? Which insertion tool, if any, did you use?

Hi Matt

Thanks for your reply.

I did not use an insertion tool (I did not know I needed one). I just soldered the wire to the contact and pushed the contact into the plug. On doing so, I realised the plug no longer fits the socket.

I did notice though that the contact I am using is a socket, whereas I think I need a pin-type contact, such as 350654-1. Never used this type of connector before.

Sorry for the newbie question, but is it necessary to buy an insertion tool?

Follow-up questions:-

  1. What is the difference between a split-pin and a pin contact
  2. What does it mean when a contact is ‘stamped’?

Your housing is compatible with both pin and socket type contacts, though if you use pins in one, you need sockets in the other. if your header uses socket contacts, which it does, then you would need pins. My apologies for not catching that on my initial inspection.

Necessary no, but it can help speed and ease the process. If you’re performing repairs on a single housing or two, it should not be strictly necessary.

Split-pin means the contact is split in two, which can give it some extra resilience against shock and vibration at the cost of being more fragile overall.

“Stamped” means the contact is created by stamping and forming a sheet of metal, as opposed to being milled down from a solid block. Stamped contacts are drastically less expensive than machined contacts, but are frequently held to be lower quality and not as good for power handling especially. That said, they suffice for most ordinary applications.

Fantastic, thanks for your detail and swift reply.

I realised my mistake too late, but I am glad to see there is a solution.

Regarding pin 350654-1 or socket 770673-1, you may find this document helpful regarding some instructions for crimping and insertion.

Hi again

I have now bought the crimp pin contact, A25405-ND, and inserted it (without an insertion tool) into the plug A97525-ND.

However, the crimp pins do not allow a clean insertion and removal of the plug to (and from) the circuit board header, A1494-ND.

When I try to insert the crimp pin alone into the header, it does insert and remove easily, but not when the crimp pin is inserted into the plug…

Finally, I have inspected the CAD drawings of each part and I see no obvious mechanical incompatibility…

Any ideas what I could be doing wrong?


Hi Manoj,

Thank you for your inquiry.

The insertion tools for these aren’t anything special, but if you don’t have one for smaller gauge wire I would use a good tweezers to tightly hold the back end of that contact while inserting.

TE Connectivity’s Instruction Sheet 408-7714 indicates inserting smaller gauge wires might be more difficult and they actually recommend using an extraction tool to insert the contacts, like 1804030-1.

Click here for Instruction Sheet 408-7714

Thanks, Kristof

I was just now looking at the UNI-MATE crimp contact Extraction Tool: A32539-ND, but it states it is “for rectangular contacts”.

However, all contacts I have seen from TE are circular in cross-section.

(This is the same extraction tool recommended in the TE Connectivity document 114-1010).

Is this extraction tool the right one for these crimp contacts?

The set of plugs and headers we are talking about are rectangular contacts, so we have that right. I read in your previous post that you were trying to use an extraction tool on A1494-ND? No extraction tool will work for that as it is a header, the contacts are molded to the connector.

Let me know if I missed something.

Hi Michael,

Sorry that I was not clear.

What I mean is:

  1. When I test if I can insert the contact pin (A25405-ND) directly into the header (A1494-ND) to see if it is the correct diameter, it inserts fine and is removable also.

  2. However, when I install the crimp pin into its plug housing (A97525-ND), the latter does not insert into the header easily. It is also very difficult to remove. I cannot understand why.

  3. As regards the Extraction Tool (A32539-ND), I understand that it can only be used “for rectangular contacts”, whereas the contacts I have seen from TE Connectivity (e.g. A25405-ND) are circular in cross-section.

Am I misunderstanding this?

Does the Extraction Tool allow me to remove contacts of circular cross-section or only rectangular cross-section?

Universal Mate-N-Lok connectors are categorized as ‘Rectangular Connectors’ The contacts used in them are considered rectangular contacts, even though they are round in shape.