Through hole flanged washer for PCB

[TimB]

Hi all

On working on a new project and need to have a PCB that you can attach cables to. I want to replicate the type you get on thermocouples plugs. I have seen inserts that have a thread but worried that it would not last long as they will be used 10's of times (not 100's)

The other option is to have the thread as an insert in the enclosure or a nut on the outside and screw the cable against the PCB. However that will damage the PCB tracking so I'm looking for a flanged washer that can be inserted and either soldered down or crimped in the hole.

Trouble is my google foo is not working well and not finding any items. The best I have found are these images of the kind of options.

Any ideas where to find such items?

Thanks Tim

[See_Mos]

Hi Tim, I have used those and found them to be very soft.  I did find a harder alternative but at the moment I can't remember the detail.  Perhaps it will come to me at four in the morning!

These aren't the ones I used but might work,  I searched for nutserts then I just put brass in the search at the rivetwise site

https://www.rivetwise.co.uk/products/index.asp?section=avdel_avsert_speed_fasteners-2103

If you are actually using themocouples  using different materials can affect the readings, in theory anyway.

[trastikata]

I used M2 brass spacers, which are easy to solder, for a similar purpose. On the bottom side I completely covered them with solder and on the top side I soldered them around, leaving about 2mm boss extrusion where the cable lugs got screwed. 

https://www.aliexpress.com/item/32968906213.html

[TimB]

What I'm looking for a is a brass or copper hollow rivet much like the one in the photo but for say an m2 screw



 

[TimB]

This might be the solution. It's a combination of the 2 systems

The brass insert is screwed in through the PCB and into the case then soldered to the board. Perhaps have them gold plated for corrosion resistance

[top204]

The company site below looks quite interesting:

https://www.pemnet.com/fastening-products/products/

[RGV250]

Hi Tim,
Not quite what you are looking for but might be an alternative idea, from the datasheet they do a M3 thread.
https://uk.farnell.com/keystone/7788/terminal-pcb-screw-1-85mm/dp/2909398?gclid=Cj0KCQiAuP-OBhDqARIsAD4XHpcjVY0N0OIzMG1hqZOVu9u1kSugHGKIvMK1MUsenU6oGksy7igESKwaApCGEALw_wcB&mckv=stPmPBeJi_dc|pcrid|460327518652|plid||kword||match||slid||product|2909398|pgrid|107884853676|ptaid|aud-984250583014:pla-299951953896|&CMP=KNC-GUK-SHOPPING-SMEC-Whoops-Remarketing-Test775&gross_price=true#anchorTechnicalDOCS

Bob

[TimB]

I want to replicate the connection style for a thermocouple.

Now I'm thinking do it more like the connector, in fact I can use bit of copper or brass much like in the tangs but solder them to the board and clamp the cable to the tangs with a nut on the underside.

[Stephen Moss]

Depending on how much height clearance you have would a small hank bush like this do the job.
Hopefully the ridged edge on the outside of the insert would be sufficient to keep it from rotating once pressed into the PCB and if you get one designed for a sheet a little thicker than the PCB there is the possibility of also soldering the protruding section of the insert to help prevent rotation.

[TimB]

What I decided in the end to do is solder tags to the board and have the nut loose in the case like a normal thermocouple connector.

[rick.curl]

In one of the posts above Les suggested PEM fasteners. I have had very good results with them. Look here: PEM broaching PCB fasteners  I have a little arbor press on my workbench that I use to install them, but in a pinch you can use a C-clamp.
BTW- There is a company called Captive Fasteners that is a second source (and less expensive) than PEM: CKF2 fasteners

-Rick

[Giuseppe MPO]

These rivets can also be used, they are not made for use in electronics but may work well.Link