Omron B3F

Versatile PCB Push Buttons With Separately Available Multi-Color Push Buttons

The Japanese company Omron produces a wide variety of electrical components, including switches. Their B3F series of tactile switches is one of the most popular used world-wide, which is why these buttons are also readily available as cheap Chinese clones.

B3F switches are available in 6x6mm and 12x12mm, plus in a multitude of configurations. They are rated for voltages up to 24V and currents of up to 50mA.

The picture shows a B3F-compatible 12x12x7.3mm push button with a corresponding A14 snap-on button cap, including transparent cover:

Great-looking push buttons with good haptics are typically fairly expensive. The B3F series is exceptionally versatile and economical: in combination with readily available colored button caps, they turn into sophisticated push buttons fit for direct user interaction. The ability to add a transparent cover for some of the button caps adds additional value, as it easily allows you to professionally label the buttons before snapping on the acryl cover.

Overview

The B3F series of tactile momentary buttons comes in two sizes (6x6mm and 12x12mm) and multiple configurations.

Without Button Caps

These buttons feature a black or yellow round or square button axis, available in different lengths. It can be directly used as a push button surface, however the small surface area and the “raw” looks encourages direct use only for internal configuration tasks that do not require regular interaction by end users.

Using Button Caps

Button caps are available in many different colors that either slide onto the round button axis, or firmly snap onto the rectangular button axis.

Button Axis Types

A button cap turns the simple push button into a versatile end-user ready sophisticated input button that can be part of panels or user interfaces. Some button caps even come with transparent covers so that you can label the button cap before you snap on the transparent cover part.

Before you cann find button caps that fit your button, make sure you understand the different button axis types:

  • Round black axis: these buttons were originally not designed to be used with button caps. The round black axis serves as a simplistic button all by its own. Smart sellers have nevertheless produced colored button caps that slide onto the round axis. Since no snapping mechanism secures the cap, and since there are no dimensional standards, you need to select the appropriate button cap inner diameter that fits your button axis, and/or the button cap might need some extra glue to be secured.
  • Square yellow axis: the switch looks more like a knob, and has a round recess in the middle. This knob is not meant to be pressed directly by a user. Instead, it serves as a snapping mechanism where appropriate button caps can be firmly snapped onto the button.

Button Caps

When you purchase B3F switches, there are many different button sizes, button axis types, and button axis shapes to choose from.

Likewise, when you want to (separately) purchase colored button caps, there are many different shapes and sizes available as well. It can be redious to find button caps that snuggly fit your button type since many sellers do not publish exact dimensions.

Instead, sellers use a type system for button caps that starts with an A, followed by a number. It seems somewhat arbitrary. Here is a table to provide some orientation:

Type Button Size Axis Remarks
A14 12x12x7.,3mm square transparent cover available
A66 6x6x7.3mm square transparent cover available
A111 6x6mm square 2.4mm
A29 6x6mm round 3.1/3.2/3.4mm
A30 6x6mm round 2.4mm
A56/A101 6x6mm round 3.1/3.4mm

Wiring

Most B3F switches come with four pins designed to be mounted on a PCB or soldered to a prototyping board. Here are the dimensions for the 6x6mm switches:

Internally, the buttons use one switch only:

Materials

Omron B3F Push Button Datasheet

Slow Website?

This website is typically very fast, and pages should appear instantly. If this site is very slow for you, then your routing may be messed up, and this issue does not only affect done.land, but potentially a few other websites and downloads as well. Here are simple steps to speed up your Internet experience and fix issues with slow websites and downloads..

Comments

Please do leave comments below. I am using utteran.ce, an open-source and ad-free light-weight commenting system.

Here is how your comments are stored

Whenever you leave a comment, a new github issue is created on your behalf.

  • All comments become trackable issues in the Github Issues section, and I (and you) can follow up on them.

  • There is no third-party provider, no disrupting ads, and everything remains transparent inside github.

Github Users Yes, Spammers No

To keep spammers out and comments attributable, all you do is log in using your (free) github account and grant utteranc.es the permission to submit issues on your behalf.

If you don’t have a github account yet, go get yourself one - it’s free and simple.

If for any reason you do not feel comfortable with letting the commenting system submit issues for you, then visit Github Issues directly, i.e. by clicking the red button Submit Issue at the bottom of each page, and submit your issue manually. You control everything.

Discussions

For chit-chat and quick questions, feel free to visit and participate in Discussions. They work much like classic forums or bulletin boards. Just keep in mind: your valued input isn’t equally well trackable there.

  Show on Github    Submit Issue

(content created Sep 28, 2024)