how many milliamps can a standard pcb header hold up to?

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Joined Apr 5, 2008

As long as YOU do not tell us wich pcb header you are using, we can not give you an answer.
There are so many types and sizes to choose from.
Locate the datasheet of the header you are using and you will have the answer.
As said the size of the PCB trace will also determine the max current.



Joined Aug 1, 2013
Why do you assume everyone know what the current limitations of a header pin is just because you do?
Why do you assume that there is such a thing as a "standard" header? Why do you assume that everyone automatically knows what you mean by "standard header" (post #1)? In this country, JST is known more for its metric components, while my guess is that your are in fact referring to an English header (0.100 pitch).

I just reviewed all of your posts in this thread. NOWHERE do you give any details about the connector - pin shape (square, round), pin thickness/diameter (0.019, 0.025, 0.031), spacing (2mm, 0.100, 0.156), or geometry (single row, double row). Each of these has a direct affect on the current rating per pin.

Since you refused to provide any details, I responded in post #11 with both a safe assumption and the datasheet rating for a header that meets one set of the above conditions. You have not acknowledged or responded to my post.

If you are asking about a board-mounted part with no identifiable markings, can you post a photo? This probably would be enough to narrow the field of possibilities to a reasonable guess.



Joined Jun 17, 2014
Hello there,

To the OP:

It is rather hard to know the specs on a connector that we find laying around in the junk box. The only way really is to try to look up your order sheets and try to figure out when you ordered it and where you ordered it from and then maybe you can get a part number. Going back to the site where you ordered it from, you might find a data sheet. With some random connector and no data sheet or part number it's very hard to rate it however because it depends on too many things as to how the connector was made and exact dimensions, and even materials used.

Given a random connector that we dont know the part number, several tests are required. For example, pump some current through the pin and try to measure the temperature rise, then pump some through adjacent pins and try to measure the rise then, see if it matters, etc. There are notes about this on the web somewhere but you'd have to look for them as i dont remember where they are offhand.

Another spec that comes into play is the contact resistance. This could vary a little from piece to piece, and also with any movement or regular vibration. I've seen some contact resistance go up into the Ohm's when moved a little due to poor contact pressure.

So in the end all we are left with are tests that we have to do ourselves if we cant find any reliable written data. This is true with almost any part except those who's specs can be guessed from the physical construction but even then it's best to look for some hard data on the part.
Sorry there is no blanket answer for this that covers all the bases, but even other simple parts like resistors are hard to rate due to various construction and material differences. One manufacturer might rate a part at 1 watt while another rates a part of the same size at 2 watts, and each manufacturer knows the secret why they have to rate it at such a rating. The only to do it without the spec's again is to test, test, test.

If you are unsatisfied with anything above then the best bet is to simply scrap the connector entirely and go out and buy a new one with a part number and that will have a data sheet which should clearly specify the current rating and perhaps some other data. Dont waste your time on parts that dont have a data sheet either as that wont help the situation :)


Joined May 19, 2014

If you don't know the answer to a question, one very good response is, "I don't know the answer, but I know where to find it." The initial answers to your question were directing you to where to find the correct answer, the data sheet. I am certain that a college professor would have given you the same answer. Although, considering your attitude, you are probably many years before you can enter college.

The attitude that you exhibited in this thread shows that you have some issues. Your life will probably be a long one, it is up to you if it will be pleasant or difficult. Don't let a bad attitude bring bad things your way or prevent the good things from reaching you.

Thread Starter


Joined Feb 20, 2016
Indeed, I'm looking at my motherboard now and I see 3 different headers.
and here lies the problem!
I was unaware there were more then one standard for a header pin for a PCB!!!

So sorry I'm not a genius and i thought i could get some help on this board!
My mistake! this board feels an awful lot like a classroom! Ask a question and get berated by the professor for not knowing the answer causing the student to never want to ask anything again. Producing sub par engineers that don't know shit!

Keep up the great work!


Joined May 19, 2014

This is a teaching forum. We gladly assist people who have worked at a problem and then come here for some help. You don't have to be a genius, you just have to had tired to solve your problem yourself before you came here.


Joined Feb 22, 2015
This is my favorite "all about circuits" reply!

Typical answer
"read the datahsheet"

Don't you think if i had found the answer in a data sheet i would not be asking?
I think this was the point when it went downhill. Your reply was grossly disproportionate to any offense you could of taken from what was a legitimate reply to your vague description. If you take such extreme offence to that then any internet forum is probably not the place for you. I've asked a fair few silly questions before and sometimes it's an obvious answer (and embarrassing) but I got over it. Bertus sums it up pretty well in his signature.

You don't have to know everything, if you know where to find it.
When you do ask questions, you may look stupid.
When you do NOT ask questions, you will STAY stupid.


Joined Mar 24, 2008
Most of the replies I would agree with. You need to show your work and where you are having problems. There are usually many solutions, all valid, to any problem. The numbers of connectors is vast, and no one knows it all.

All the people here are volunteers, people willing to share their expertise. When treated with respect they respond in kind, if not then you will reap what you sow.


Joined Jun 19, 2012
"Empathy is the experience of understanding another person's condition from their perspective. You place yourself in their shoes and feel what they are feeling. Empathy is known to increase prosocial (helping) behaviors."

Seems like we all need a bit more of this.

What surprises me is the number of posts that are utterly lacking in context or detail, which comes from a general lack of Empathy.
That ability to step outside one's own perspective, to perceive that others may not possess the same knowledge, context or experience.

It takes Empathy to ask good questions.
It takes Empathy to give good answers.


Joined Jun 26, 2012
Whew! I deleted several posts from durable126 that contained abusive and/or foul language. Whatever emotions are involved here, such behavior is out of line and a clear TOS/UA violation.
Apologies for any I missed and for the resulting disjointed thread.
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