Anyone have a source for decent cheap binding posts? - Page 1
Forum section: electronics / general

author: PascalNE
author_rank: Regular Contributor
timestamp: May 12, 2025, 10:45:17 am
content: Hello,I am currently putting together a measurement switching system and need a lot of binding posts. Ideally I'd buy 10 Pomona 3770s but my budget doesn't quite stretch that far.I've had a look on Aliexpress/Alibaba and of course they all claim to be "Gold plated Solid copper"So I wondered if anyone has a reliable seller for good copper or maybe brass binding posts for around ~£5 (6EUR) or less with good thermal EMF properties suitable for precision measurement.I feel like there must be some Chinese manufacturer making them?Thanks, Pascal.

author: The Soulman
author_rank: Super Contributor
timestamp: May 12, 2025, 11:08:11 am
content: I use these:https://www.reichelt.com/nl/en/shop/product/4-mm_pole_terminal_gold-plated_black-128877Not rated/suitable for nanovolts but good enough for almost everything else.Minimizing the thermal gradient and keeping it the same across both the positive and negative terminal is imho more important than the base (copper vs brass) material.

author: PascalNE
author_rank: Regular Contributor
timestamp: May 12, 2025, 11:33:11 am
content: Thanks those look good if anyone knows of any that are even cheaper let me know, since I need so many. But I will keep those in mind.

author: PascalNE
author_rank: Regular Contributor
timestamp: May 12, 2025, 11:35:06 am
content: And I realise this is a whole other question but what are the drawbacks of nickel vs gold plating?

author: tatel
author_rank: Frequent Contributor
timestamp: May 12, 2025, 12:37:06 pm
content: More EMF. But, if thermal difference is gone after some time, there Will be less/no EMF. Usually plating is thin enough that temperatura difference is minimal after some time. Gold does have EMF but is among the lowest, so time to reach lesser EMF will be less. Copper/copper would be probably the best, but It oxidizes and EMF goes through the roof. Gold does not oxidizes.

author: Kosmic
author_rank: Super Contributor
timestamp: May 12, 2025, 03:59:23 pm
content: Quote from: PascalNE on May 12, 2025, 10:45:17 amIn term of copper binding post, everything is around 10US$ (Pomona 3770 = 13$, Mueller BU-P3770 = 12$, Chinese TBP2 = 10$).

author: PascalNE
author_rank: Regular Contributor
timestamp: May 12, 2025, 04:08:26 pm
content: Yeah that makes sense the material cost has to be quite high for copper. I guess now I'll just try to find the cheapest gold plated brass or maybe nickel plated ( if it doesn't matter too much) It's a shame you can't really buy them from sites from Alibaba or Aliexpress since they just lie

author: MarkF
author_rank: Super Contributor
timestamp: May 12, 2025, 04:17:50 pm
content: If you don't actually need the binding post and only need a banana jack,I have found these to be nice and you can get them in various colors.https://www.digikey.com/en/products/detail/cinch-connectivity-solutions-johnson/108-0902-001/5929

author: PascalNE
author_rank: Regular Contributor
timestamp: May 12, 2025, 04:37:50 pm
content: I think I'd like to have the binding post for attaching spade lugs or wires directly.https://www.sparkfun.com/binding-post-red.htmlthese sparkfun ones are very cheap and I think they are identical tohttps://www.mouser.co.uk/ProductDetail/Shin-Chin/R1-09-R?qs=YFJnwOc%252BsAd24HskFnzsEA%3D%3D(looking at the data sheet) and they claim to be nickel plated brass.Certainly not metrology grade though. Maybe I'll get the cheap ones and upgrade down the line when I have more to spend. And what order of magnitude will the EMFs be?

author: voltsandjolts
author_rank: Unknown
timestamp: May 12, 2025, 04:39:26 pm
content: I findCliff postsare good quality for the money, but I may be biased because they are uk manufacturerhttps://www.cliffuk.co.uk/

author: PascalNE
author_rank: Regular Contributor
timestamp: May 12, 2025, 04:56:36 pm
content: Yeah those cliff ones look good actually thanks, I just saw a review complaining the sparkfun ones saying they weren't great quality.My only trouble is for the tp1 which I think is what I want it doesn't mention the materialhttps://www.cliffuk.co.uk/products/terminals/single.htm#tp1And I don't blame you for being biased, the fact that they are made in the uk while it doesn't guarantee it it is an indicator of quality

author: PascalNE
author_rank: Regular Contributor
timestamp: May 12, 2025, 05:05:43 pm
content: I didn't scroll down far enough on the datasheethttps://static.rapidonline.com/pdf/17-0230e.pdfbut yes they are nickel plated brass so I'll probably go with those.

author: manganin
author_rank: Regular Contributor
timestamp: May 12, 2025, 07:05:31 pm
content: Quote from: PascalNE on May 12, 2025, 10:45:17 amWas used in many British metrology equipment:Cliff CL15501Ahttps://www.tme.eu/en/details/cl15501a/4mm-banana-sockets/cliff/Cliff CL15511Ahttps://www.tme.eu/en/details/cl15511a/4mm-banana-sockets/cliff/Precisely machined, thick gold plating and the plastic didn't crack.Not sure if the quality is the same anymore.

author: PascalNE
author_rank: Regular Contributor
timestamp: May 12, 2025, 07:20:42 pm
content: I think I'll go for the TP1s it seems like the only difference is nicer plastic and gold plating (but double the price)Maybe when I have more time and money on my hands I can buy up a few and do some comparisons and publish my results here might be an interesting experiment especially since they mostly don't list many specs

author: tszaboo
author_rank: Super Contributor
timestamp: May 12, 2025, 08:25:14 pm
content: Quote from: PascalNE on May 12, 2025, 04:08:26 pmYeah, I mean copper is 6 EUR per KG, and very easy to machine, like butter. It totally explains why a binding post is 16 EUR.Some Youtuber suggested to always start a business where customers don't know how much your product is supposed to cost.

author: PascalNE
author_rank: Regular Contributor
timestamp: May 12, 2025, 08:37:22 pm
content: To be fair the volume must be pretty low and they tend to use more exotic tellurium copper which is more like 20EUR/Kg (based on my limited research) but I agree they probably have pretty good margins on £10 per binding post.

author: bdunham7
author_rank: Super Contributor
timestamp: May 12, 2025, 09:13:39 pm
content: Quote from: tszaboo on May 12, 2025, 08:25:14 pmUm, really? Copper is very difficult for many machining operations, it is like taffy not butter. The sole reason that they use tellurium copper alloys in high-end products is that it makes the copper easier to machine. The claim is often made that CuTe is like free-machining brass but it is't even close to that when you drill small holes or tap them. It's just not as terrrible as soft or ETP copper.

author: manganin
author_rank: Regular Contributor
timestamp: May 12, 2025, 09:56:43 pm
content: Quote from: manganin on May 12, 2025, 07:05:31 pmIncluding standard resistors.

author: PascalNE
author_rank: Regular Contributor
timestamp: May 12, 2025, 10:06:30 pm
content: If I do end up doing a comparison what are the most important parameters I should test for that people would want to know?

author: bdunham7
author_rank: Super Contributor
timestamp: May 12, 2025, 11:16:20 pm
content: Quote from: PascalNE on May 12, 2025, 11:35:06 amFluke and probably other manufacturers warn you not to use nickel plated banana plugs for precision voltage measurements. The thermal EMFs are much higher (I've seen them, they are an order of magnitude worse then gold-plated) and they may not fully dissipate. Sometimes there is a continuous heat transfer outward from a device that is warm inside like a typical DMM and thus there is always a differential across the less (thermally and electrically) nickel plating. I know some plugs have gold plating over nickel flash but this actually doesn't seem to be as much of a problem. I would guess that is because you have two opposing junctions that are fairly well thermally matched, but IDK for sure.

author: PascalNE
author_rank: Regular Contributor
timestamp: May 12, 2025, 11:21:08 pm
content: I see perhaps I will go for the CL15501A (gold plated brass). This may be a silly question but what order of magnitude would it be for nickel or for gold?Just want to know if it will affect the ranges I am interested in.

author: bdunham7
author_rank: Super Contributor
timestamp: May 12, 2025, 11:29:20 pm
content: Quote from: PascalNE on May 12, 2025, 11:21:08 pmOf course it depends on the relative and absolute temperatures, but perhaps <1.5µV/C vs 20µV/C? Even with a warm DMM the junctions will settle to under a 1C gradient so perhaps nanovolts vs a few microvolts after you let things settle. And of course, YMMV-that's just what I've seen.

author: PascalNE
author_rank: Regular Contributor
timestamp: May 12, 2025, 11:34:58 pm
content: Oh wow that is significant I wonder if there is any publicly available experiment results on different materials? I'll have to look around.

author: zlymex
author_rank: Frequent Contributor
timestamp: May 13, 2025, 01:03:35 am
content: I had some 3770 compatible good/cheep low thermal EMF pure copper binding posts from a fellow with surface passivation or gold plated.Bought from 闲鱼(goofish, cousin of Taobao and Aliexpress) at about 1.7 USD each.https://www.goofish.com/item?id=711428863560

author: zlymex
author_rank: Frequent Contributor
timestamp: May 13, 2025, 01:17:29 am
content: Quote from: PascalNE on May 12, 2025, 10:45:17 amNope.Most of the "Gold plated" are actually Nitric Oxide or Titanium Nitride processed, and "Solid copper" is actually brass.In Chinese, brass and bronze are all "copper"(with "alloy" omitted).There are two well known binding posts within Chinese amature circle:one is TBPn(n from 1 to 5), copper or tellurium copper, w or w/o gold plated/flashed,the other is redtony's copper one, low EMF and low priced.They all make those binding posts by themselves with special machinery process to overcome the ductility and plasticity problems.

author: PascalNE
author_rank: Regular Contributor
timestamp: May 13, 2025, 01:27:33 am
content: Yeah I thought so, not sure if I can trust/use this website though

author: CatalinaWOW
author_rank: Super Contributor
timestamp: May 13, 2025, 01:29:34 am
content: Quote from: bdunham7 on May 12, 2025, 11:16:20 pmWhile low EMF potential is desirable it seems there would be another solution. An insulated boot across the cable attachment to move the thermal gradient beyond the metal interfaces.Has anyone tried this and have results to share?

author: zlymex
author_rank: Frequent Contributor
timestamp: May 13, 2025, 04:02:39 am
content: Quote from: CatalinaWOW on May 13, 2025, 01:29:34 amSomething like these?

author: Simmed
author_rank: Frequent Contributor
timestamp: May 13, 2025, 04:06:43 am
content: is there a TBP/redtony webshop ?Quote from: zlymex on May 13, 2025, 01:17:29 am

author: Psi
author_rank: Super Contributor
timestamp: May 13, 2025, 04:13:38 am
content: If you just order 1 each from 10 AliExpress stores where the item look good from the pic and they're asking a fair price for a quality item (ignore anything ultra cheap) then you usually find 1 or 2 sellers selling something that is actually decent quality.But of course you have to actually do that and pay for 10 items in order to find the 1 or 2 good sellers who you can order more from. So it takes some effort/time.It can actually be worthwhile doing that if you want to order 100 of them.If you want more than that it's best to spend some time finding somewhere on alibaba that actually makes the good quality stuff.Sometimes that is easier to do by first buying from aliexpress and then backtracking the good items to find out what factory listed on Alibaba actually made them.

author: zlymex
author_rank: Frequent Contributor
timestamp: May 13, 2025, 05:29:48 am
content: Quote from: Simmed on May 13, 2025, 04:06:43 amredtony's:https://www.goofish.com/personal?userId=993202930TBPn:https://shop68211206.taobao.com/I know the boss(of the company that makes TBPn and the owner of the taobao shop) who is very energetic.

author: voltsandjolts
author_rank: Unknown
timestamp: May 13, 2025, 07:06:45 am
content: Is that him searching for Tellurium?

author: PascalNE
author_rank: Regular Contributor
timestamp: May 13, 2025, 07:56:53 am
content: I've spent a lot of time looking at AliExpress there's not really any binding posts for test and measurement devices really.I think I might buy a few from "redtony" just to check the quality even after postage I don't think it'll cost more than £10. (I will use a package forwarding service)I also got these recommendedhttps://www.goofish.com/item?id=720090510951&categoryId=0which I prefer the look of the seller seems to be a bit of a voltnut which lends some legitimacy.Also if anyone happens to want some cliff ones theyve just reduced the price on rapid electronics really farhttps://www.rapidonline.com/cliff-cl1505-black-4mm-terminal-17-0245So I think I'll buy a pair of thesehttps://www.goofish.com/item?id=720090510951&categoryId=125958001pure copper binding posts seller "nimolv"~$2.73And a pair of thesehttps://www.goofish.com/item?id=711428863560&categoryId=125958001pure copper no plating binding posts seller "redtony" ~$1.67And a pair of thesehttps://www.goofish.com/item?id=674240096284&categoryId=125958001gold plated copper seller "redtony" ~$2.09

author: PascalNE
author_rank: Regular Contributor
timestamp: May 13, 2025, 11:52:07 am
content: If anyone in the uk is interested in getting some of these chinese ones and wants to split the costs send me a PM

author: Simmed
author_rank: Frequent Contributor
timestamp: May 13, 2025, 12:50:43 pm
content: Quote from: zlymex on May 13, 2025, 05:29:48 amyou know about this shop ? TB ID 684620318735

author: zlymex
author_rank: Frequent Contributor
timestamp: May 13, 2025, 03:33:57 pm
content: Quote from: Simmed on May 13, 2025, 12:50:43 pmI don't know this. I asked in my group one member knows.

author: PascalNE
author_rank: Regular Contributor
timestamp: May 13, 2025, 03:39:52 pm
content: Have you ever heard of the seller of this itemhttps://www.goofish.com/item?id=720090510951&categoryId=0and thank you for your help there's a lot of interesting things on goofishannoying that I'm unable to make an account and can only buy through cssbuy though.

author: zlymex
author_rank: Frequent Contributor
timestamp: May 13, 2025, 05:50:17 pm
content: Quote from: PascalNE on May 13, 2025, 03:39:52 pmNot really, but they all look genuine, and the copper binding posts look very similar to mine that bought many years ago from somewhere else.

author: PascalNE
author_rank: Regular Contributor
timestamp: May 13, 2025, 08:52:15 pm
content: Just placed an order using CSSbuy I bought 1 unplated and 1 plated from "redtony" and a pair of those unplated ones from "nimolv" when they arrive (probably in a while) I'll make a post reviewing them all maybe comparing against similarly priced nickel plated brass posts. And if they are good I'll make a big order.Thanks for all your suggestions.

author: Kosmic
author_rank: Super Contributor
timestamp: May 16, 2025, 01:16:00 pm
content: Quote from: zlymex on May 13, 2025, 01:03:35 amThank you zlymex for the link. I did not know about goofish.I particularly like those banana binding post. It's going to be useful on my Prema 5017

author: PascalNE
author_rank: Regular Contributor
timestamp: May 18, 2025, 02:52:29 pm
content: I've made a list of these cheap ppm compatible binding posts herehttps://www.eevblog.com/forum/metrology/chinese-metrology-accessories-list/(just in case anyone finds this topic in the future)

author: Alex Nikitin
author_rank: Super Contributor
timestamp: May 18, 2025, 03:28:27 pm
content: The isolation material also matters.CheersAlex