How to breadboard with large lead components (such as TO-220)?

Question

What type of connector, terminal block, header, or socket can plug into a breadboard on one side and accept large lead components (such as a TO-220, lead is 0.05" wide)?

Background

Breadboards have 0.1" (2.54mm) pitch. Although I can't find the hole width and length documented anywhere, they work well with 22 AWG wire, which has 0.025" (0.64 mm) diameter, so my rule of thumb is that a component lead should be that size.

As discussed here, components such as TO-220s don't really fit that size. This [datasheet] shows leads between 0.45" to 0.55". Likewise, diodes, switches, and trimmers don't usually fit breadboards either.

Understanding that breadboards don't work well for demanding circuits, there's still a lot of experimental and educational value in being able to experiment with simple circuits using these components. What are good ways to breadboard with such components?

One method that has worked well is simply using alligator clips. But this gets bulky and tangled, and it's hard to get the clips on TO-220 leads individually without causing a short.

Question

Are there other adapters or connectors that can temporarily connect larger lead components, like TO-220s, to a breadboard? I've looked at female headers and terminal blocks, and surprisingly can't find any information about what type of lead diameter they take.

Concepts

Ideally would be a header with 0.1" pitch pins, but sockets that can handle leads of up to 0.06". However, this would be impossible, since 0.06" x2 > 0.1"! A realizable design would be a terminal block or socket with pins at an integer multiple of 0.1". For example, a header block with pitch 0.2", with holes of diameter 0.06".

(Surprisingly, the hole size is not specified or drawn on any of the terminal blocks or headers I've examined.)

So: What type of connector, terminal block, header, or socket can plug into a breadboard on one side and accept large lead components (such as a TO-220, lead is 0.05" wide)?

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Update

Experimentation shows that the holes in both standard headers and breadboards (at least the ones I have) aren't square, but rectangular! It's a pity I can find no drawings of the holes (neither breadboard nor header), but the TO-220 fits both fine if I rotate it.

Unfortunately, it needs to be rotated the wrong way! That is, on the breadboard, all 3 leads in the same row; and on the header, with only one lead in the header, the other two sticking out.

This may, however, be the beginning of a solution:

• Find headers whose hole alignment matches the orientation of the leads; or
• Perhaps there are terminal blocks or other headers that accommodate leads in both ways
• Stack three headers next to each other (not sure if this will fit); or
• Twist the leads 90 degrees (not sure if they will fit without shorting each other); or
• Another creative idea...

Answer 1

I just solder short solid (not stranded) copper wires to the pins. Arrange to match the breadboard grid. #24 AWG works well.

Answer 2

As commented a good option is to solder a short wire to each lead, 1 or 2 cms long.

Otherwise this clips are a bit more bulk but work very well and are easy to attach. Also for potentiometers and other components:

(images from aliexpress)

I use them a lot. Of course you have to be careful because the component will be lying around on the table, but for some quick connections without soldering are the best.

There are also with banana connector for the DMM, to have the black probe attached at some point. And others with very small double hooks to attach to SMD IC leads, very nice.

Answer 3

Since some of the answers appear as comments, and others are off-site, I'm aggregating them here.

1. Use pliers to twist each lead 90 degrees. Surprisingly, the sockets on a breadboard are rectangular, not square, and so this should usually work!
2. Jam them into the breadboard. Opinions (experience?) differ if this will damage the breadboard. You could always dedicate a small area of the breadboard for this.
3. If you don't want to harm the breadboard, use a small 0.1" header as an interface, and jam the leads into that.
4. Use a TO-220 socket, which should fit. Sullins seems to be the only active manufacturer, though Molex used to (still available on eBay). These can be expensive.
5. Use a screw (or screwless) terminal block. The 0.1" pitch should still accommodate thick leads. Alternatively, try a 0.2" pitch, and see if it can go into every other breadboard hole.
6. Solder on 22 AWG wire.
7. Use test grabber clips with DuPont terminations or other clips.