What are the hole dimensions for 0.1" pitch headers?

Question

What are the hole dimensions for 0.1" pitch headers?

As discussed in How to breadboard with large lead components (such as TO-220)?, holes on standard 0.1" pitch headers are:

1. Rectangular (not square or circular!)
2. Accommodate large leads, such as TO-220, in one orientation, but not the other
3. Don't seem to be documented (not as a standard and not on any manufacturer data sheets I've found)

All 3 of those properties apply to breadboard sockets as well.

What are the hole dimensions? Either as a standard or as a representative component from a vendor.

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Clarification

To clarify, my question is not about the dimensions of the pins connecting the header to the board. Rather, I'm asking about the dimensions of the receptacle where the component connects to the header.

Answer 1

For less standard machined-pin headers from companies like preci-dip or mill-max, you can get the information fairly easily--for instance, mill-max's 801 series headers (which accept standard 25 mil square pins, or round pins from 25 to 37 mils in diameter) specify that they use their #47 contact, which you can then find not only dimensions for, but even insertion and removal force specifications.

Image taken from this datasheet.

For industry-standard 100-mil headers, this isn't information that's all that easy to find; they usually just specify that the header will mate with a standard 25 mil square pin. I was able to find this specification for a 2-pin jumper from Amphenol:

Image from this datasheet

I've not been able to find any such information from other sources, however, and there's no guarantee the dimensions of the jumper will match the dimensions of standard headers in the series. It's possible you may be able to rely on 3D models provided by companies that tend to have pretty accurate 3D models, like Samtec, but I can't say with any certainty.

Answer 2

0.1" (2.54mm) pitch headers are designed to be soldered into a PCB. One standard (there are others, such as those with round screw-machine pins) has 0.025" (0.635mm) square pins.

A typical recommended PCB hole diameter is 1.1mm round. For hand assembly this is very loose, but it does account for almost any imaginable build up of tolerances and for machine insertion. The diagonal dimension of a 0.64mm pin is about 0.9mm and the corners are not exactly square, and would only contact the hole at the corners anyway, so you can certainly get away with 0.9mm for short runs of 4 or 5 pins, and 1mm is quite loose.

Answer 3

"0.1" pitch headers" is vague, as there are literally 100's of different PCB headers with a 2.54 mm pitch. So let's pick one as an example.

A popular one is a shroudless pin header. The size of its square pins is 0.025 inch = 0.635 mm. The diagonal is 0.9 mm = 0.035 inch. Therefore, a 0.045 inch / 1.1 mm diameter PCB hole will work fine.

Accommodate large leads, such as TO-220, in one orientation, but not the other

Here are some: https://www.digikey.com/short/ppqjz22q

Let's pick this one: Sullins TCC05DCSN-S1403, https://www.digikey.com/en/products/detail/sullins-connector-solutions/TCC05DCSN-S1403/4213430

{Source: Digikey}

The pins are in a 0.1 inch grid, perfect for a breadboard. The size is 0.025 inch, so it will fit fine in a breadboard.