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What Are 3-Pin and 5-Pin Keyboard Switches?
When buying mechanical keyboard switches, you will often come across the terms 3-pin and 5-pin.
But what exactly do those pins mean, and does the difference affect compatibility with your keyboard?
The main difference is simple: 5-pin switches have two additional plastic stabilizing pins. They do not have more electrical connections than a standard 3-pin switch.
Quick explanation
A standard 3-pin switch has two metal electrical pins and one central plastic pin. A 5-pin switch also has two additional plastic stabilizing pins. 5-pin switches are more stable when mounted directly to the PCB, while 3-pin switches are mainly intended for use with a plate.
1. What is a 3-pin keyboard switch?
A standard 3-pin MX-style switch has three important mounting points on the bottom:
- 1 central plastic pin;
- 2 metal electrical pins.
The central plastic pin positions the switch in the PCB.
The two metal pins provide the electrical connection to the keyboard.
2. What is a 5-pin keyboard switch?
A 5-pin switch has the same parts as a 3-pin switch, plus two additional plastic support pins.
You therefore have:
- 1 central plastic pin;
- 2 metal electrical pins;
- 2 additional plastic stabilizing pins.
Those additional two pins have no electrical function.
They only help the switch sit more firmly and straight in the PCB.
3. Are all five pins electrical?
No.
This is one of the most common misunderstandings.
On a standard 5-pin mechanical switch, normally only two pins are metal electrical contacts.
The other three are plastic:
- the central mounting post;
- two additional stabilizing pins.
4. 3-pin vs 5-pin in one table
| Feature | 3-pin | 5-pin |
|---|---|---|
| Metal electrical pins | 2 | 2 |
| Central plastic pin | 1 | 1 |
| Additional stabilizing pins | 0 | 2 |
| Total number of points | 3 | 5 |
| PCB stability | Lower | Higher |
| Suitable for 5-pin PCB | Yes | Yes |
| Suitable for 3-pin PCB | Yes | Only after removing the extra pins |
5. Why do 5-pin switches exist?
The additional plastic pins provide more stability.
This is especially useful in keyboards where the switches are mounted directly to the PCB.
The additional pins help prevent the switch from:
- sitting crooked;
- rotating during installation;
- moving during use.
6. What does PCB-mount mean?
5-pin switches are often called PCB-mount switches.
The additional stabilizing pins go directly into dedicated holes in the PCB.
This gives the switch additional support from the circuit board itself.
7. What does plate-mount mean?
3-pin switches are often called plate-mount switches.
With this construction, the keyboard plate helps hold the switch firmly in place.
Because the plate already provides stability, the two additional plastic PCB pins are less necessary.
8. Does a 5-pin switch always need a plate?
No.
A 5-pin switch can actually be especially useful in builds without a traditional plate.
However, 5-pin switches can also be used normally in keyboards with a plate, as long as the PCB has the additional holes.
9. Does a 3-pin switch fit in a 5-pin PCB?
Yes.
A 3-pin switch normally fits without any problems in a PCB that has five holes for each switch position.
The two additional holes simply remain unused.
10. Does a 5-pin switch fit in a 3-pin PCB?
Not directly.
A 3-pin PCB does not have holes for the two additional plastic stabilizing pins.
As a result, the switch cannot be fully inserted into the PCB.
11. Can you convert a 5-pin switch to 3-pin?
Yes.
The two additional plastic stabilizing pins can be clipped off.
After that, the switch has practically the same mounting footprint as a 3-pin switch.
12. How do you remove the extra pins?
The two outer plastic pins can carefully be clipped off using, for example:
- flush cutters;
- small side cutters;
- suitable precision tools.
Only remove the two additional plastic stabilizing pins.
Never cut off the metal contact pins or the central plastic pin.
13. Is clipping a 5-pin switch permanent?
Yes.
Once the two plastic pins have been removed, you obviously cannot put them back.
The switch will still function normally, but it will no longer have the additional 5-pin stabilization.
14. Does a clipped 5-pin switch work normally?
Yes, as long as only the two additional plastic stabilizing pins have been removed.
These pins have no electrical function.
15. Is 5-pin better than 3-pin?
Not necessarily.
5-pin mainly provides additional mechanical stability.
If your keyboard uses a sturdy plate, the difference in everyday use may be small.
16. Does 5-pin affect the sound?
Not directly.
The two additional plastic pins do not change the electrical or internal switch mechanism.
Any differences in sound are more likely to come from:
- how firmly the switch is mounted;
- the plate;
- PCB;
- case;
- foam;
- keycaps;
- the switch itself.
17. Does 5-pin affect switch feel?
The internal force curve does not change.
A 45g linear, for example, keeps the same spring force regardless of whether the housing uses 3-pin or 5-pin mounting.
A more stable mounting can make the complete keyboard feel slightly more solid.
18. Are 5-pin switches better for soldered keyboards?
They can be useful.
The additional stabilizing pins help keep the switch straight before and while it is being soldered.
A good plate can also provide a lot of stability.
19. Are 5-pin switches better for hot-swap keyboards?
Not automatically.
The most important thing is whether the PCB actually supports five holes.
Many modern hot-swap PCBs support 5-pin MX-style switches, but this does not apply to every keyboard.
20. How do you check whether your keyboard supports 5-pin?
Check the PCB or product specifications.
At a 5-pin switch position you will usually see:
- one larger central hole;
- two holes for the metal contacts;
- two additional small holes for the stabilizing pins.
If the last two holes are missing, the PCB only supports the 3-pin footprint without modification.
21. Can the plate prevent a 5-pin switch from fitting?
Normally the PCB is the deciding factor for the additional pins.
The two additional stabilizing pins run through to the PCB and not into the plate.
The plate opening does, of course, still need to be suitable for the switch format being used.
22. Are 3-pin switches less stable?
Without a plate, they can be less stable than 5-pin switches.
With a sturdy plate, however, the switches are already held securely in place.
That is why 3-pin switches work perfectly well in many keyboards.
23. Are 5-pin switches more stable?
Yes, especially when the PCB supports the additional pins.
The two extra support pins reduce movement and help position the switch straight.
24. What is better for a plateless keyboard?
For a plateless build, 5-pin is generally more attractive.
Without a plate, the PCB has to provide more of the mechanical stability.
The two additional stabilizing pins help with this.
25. What is better for a keyboard with a plate?
Both 3-pin and 5-pin can work perfectly well.
If the PCB supports 5-pin, you usually do not need to choose based on pin count alone.
26. Are 3-pin switches cheaper?
Not necessarily.
Price is influenced much more by:
- brand;
- materials;
- spring;
- factory lubrication;
- switch design;
- production volume.
27. Are 5-pin switches common today?
Yes. Many modern MX-style switches come with a 5-pin housing.
This gives users the additional mounting option when their PCB supports it.
28. Do linear, tactile and clicky switches have different pin layouts?
The switch type does not determine the pin count.
You can find both 3-pin and 5-pin variants among:
29. Can you tell from the top whether a switch is 3-pin or 5-pin?
Usually not.
You need to look at the bottom of the switch.
There you can immediately see whether the two additional plastic stabilizing pins are present.
30. Are 3-pin and 5-pin switches electrically the same?
With standard MX-style mechanical switches, the basic electrical connection is the same: two metal contacts.
The additional pins on the 5-pin version are only there for mechanical support.
31. Does 3-pin vs 5-pin apply to all keyboard switches?
No.
These terms are mainly used for standard MX-style mechanical switches.
Other switch systems may use a different footprint, such as:
- low-profile switches;
- optical switches;
- Hall Effect switches;
- proprietary switch systems.
Therefore, always check the actual compatibility with your keyboard.
32. Which should you choose?
| Situation | Choice |
|---|---|
| PCB only supports 3-pin | 3-pin or modified 5-pin |
| PCB supports 5-pin | 3-pin or 5-pin |
| Plateless build | 5-pin has an advantage |
| Keyboard with sturdy plate | Both work well |
| Maximum compatibility without modification | 3-pin |
| Maximum PCB stability | 5-pin |
33. Common mistakes
- Thinking a 5-pin switch has five electrical contacts.
- Buying 5-pin switches without checking PCB compatibility.
- Clipping the wrong pins.
- Thinking 5-pin automatically sounds better.
- Thinking 3-pin switches do not fit in a 5-pin PCB.
- Assuming every hot-swap PCB automatically supports 5-pin.
Conclusion
The difference between 3-pin and 5-pin keyboard switches is mainly about mechanical stability.
A 3-pin switch has one central plastic mounting pin and two metal electrical contacts.
A 5-pin switch adds two additional plastic stabilizing pins.
A 3-pin switch normally fits directly into a 5-pin PCB. A 5-pin switch does not fit directly into a 3-pin PCB, but the two additional plastic pins can be removed.
If your keyboard supports 5-pin, you can normally use either type. In plateless builds, 5-pin has an additional advantage because of the improved stability.
Always check your keyboard's PCB footprint before purchasing.