Switch pins are the one compatibility question that stops a build before it starts. You have found switches you like, and now you need to know whether they will physically fit the board you own. The short version is that 3-pin switches fit almost everything.
⚡ Quick answer: A 3-pin switch fits any PCB, including boards built for 5-pin. A 5-pin switch only fits a PCB with the two extra holes. If you have 5-pin switches and a 3-pin board, you can clip the two plastic legs off with flush cutters and they will work fine.
What the pins actually are
Every mechanical switch has three metal parts on the bottom: two electrical contacts that carry the signal, and a central plastic post that keeps the switch aligned. That is a 3-pin switch, sometimes called plate mount.
A 5-pin switch adds two plastic legs either side of the centre post. They carry no current at all. Their only job is to hold the switch straight while you solder it, which matters when there is no metal plate above the PCB doing that for you. That is why 5-pin switches are also called PCB mount.
So the pin count is not a quality or performance difference. The same switch is often sold in both formats.
Which combinations work
| Your switch | Your PCB | Result |
|---|---|---|
| 3-pin | 3-pin | Fits |
| 3-pin | 5-pin | Fits, the extra holes stay empty |
| 5-pin | 5-pin | Fits |
| 5-pin | 3-pin | Does not fit until you clip the legs |
Only one of those four is a problem, and it takes about a minute per switch to solve.
How to clip 5-pin switches down to 3-pin
- Hold the switch with the pins facing you and find the two plastic legs either side of the centre post.
- Cut them flush with the switch housing using flush cutters or sharp nail clippers. Do not cut the centre post, and do not touch the two metal pins.
- Check the base is flat. A stub left behind will hold the switch off the PCB and cause a key that does not register.
⚠️ Before you clip a whole set: do one switch, seat it in the board, and confirm it sits flush and registers. Clipping is not reversible, and finding out at switch 60 that you were cutting too shallow is a bad afternoon.
Hot-swap boards
Hot-swap sockets take the two metal pins, so the same rule applies: 3-pin always works. Many hot-swap PCBs do include the extra holes for 5-pin switches, but not all of them, and budget boards frequently skip them.
Alignment matters more on hot-swap than on soldered boards. Bent pins are the most common cause of a dead key after a switch swap. Look at the underside of every switch before it goes in, and straighten anything that is not parallel with a pair of tweezers.
Which should you buy?
If your board takes either, buy 5-pin. The extra legs make the switch sit straighter, which is genuinely useful on a plateless build and harmless everywhere else. If you are unsure what your board takes, or you want one set of switches you can move between boards later, buy 3-pin and stop worrying about it.
Pin count should not drive which switch you choose. Pick the feel you want first, then match the format. Our best linear switches roundup ranks the options for typing and everyday use, and if you are buying for gaming, our best linear switches for gaming guide covers actuation weight and speed switches.
Frequently asked questions
Does clipping the legs damage the switch?
No. The plastic legs are alignment aids and carry no signal. A cleanly clipped 5-pin switch performs identically to a 3-pin one. The only risk is cutting the centre post or a metal pin by mistake.
How do I tell what my PCB takes without buying anything?
Pull one switch out, or look at an empty socket. Count the holes around the centre opening. Two small holes either side means it accepts 5-pin. No extra holes means 3-pin only.
Are 3-pin switches worse than 5-pin?
No. Feel, sound, actuation force, and durability are unaffected. Manufacturers sell the same switch in both formats, and the difference exists purely to help with mounting.
Can I mix 3-pin and 5-pin switches in one board?
Yes, as long as the PCB accepts 5-pin. There is no electrical difference, so a board with both is perfectly normal and often happens when you replace a few switches from a different set.
Last Updated: 29 July 2026
By: Elizabeth & Olivia