This article requires additional photographic illustration — need photo of opened switch with diode (for this and the diode page)

Variants of the Cherry MX switch

Cherry MX shipping boxes

A keyboard with MX Blue switches

MX switches with Hirose Cherry branding and keycap mount

Cherry MX is the most popular line of keyswitches used in mechanical computer keyboards.

History

Designed by Cherry, they were introduced on 7 November 1983[1] and were initially available only in a linear (smooth), light-resistance version.[Citation needed] An entire family of Cherry MX variants was subsequently developed with combinations of these characteristics:

Light to heavy force

With or without tactile feedback (a "bump" the typist can feel on actuation)

With or without auditory feedback (clicky/non-clicky)

These variants are generally referred to by stem colour. Cherry officially refers to most switch types by article number, but their newest switch types are indeed referred to by community-style monikers on their website.

The exact history of the product line is not yet clear. In July 1985, the series officially comprised MX Black, MX Linear Grey (for space bars in MX Black keyboards), MX White, and MX Click Grey (for space bars in MX White keyboards). MX Lock appears to have already existed at this point (found in a Xerox keyboard made by Hirose Cherry), but it was not included in the 1985 German MX datasheet.

The part numbers were divided into linear and tactile, with the model character being numeric for linear switches (MX1A-11__ and MX1A-21__) and alphabetic for tactile switches (MX1A-A1__ and MX1A-B1__). MX Lock was identified as "3", but MX Red was strangely identified as "L" (with "H", "I", "J" and "K" currently unaccounted for), with the much later MX Nature White getting "4" following on from MX Lock.

The patent, filed in 1983, describes the hysteresis mechanism, but says nothing about audible feedback. It would appear that the click sound was originally suppressed with grease; MX Blue was a later addition to the series after MX Clear, and it was permitted to emit a click sound.

The 1985 MX datasheet lists a rated lifetime of 20 million keystrokes for both linear and tactile types. The 1994 MX brochure lists the lifetimes as 500 k (MX Lock), 20 M ("soft" and "click" types, where "soft" may refer to MX Clear), and 50 M for "linear" and "ergonomic" types (where "ergonomic" is MX Brown). From 2017, the whole series got rated for 50 M keystrokes, with MX Lock having gone end of life.

From November 1st, 2019 all variants are supposed to be manufactured with a different leaf spring and contacts, supposed to lead to a bounce time of less than 1 ms. In 2020, linear MX variants and MX Brown got modified stems (and possibly housing), with a new rating of 100 M keystrokes. [2]

Design

Cherry MX switches have gold crosspoint contacts. The contact mechanism has one small static terminal, and a movable leaf that is folded against itself at the top. At least two designs of contact mechanism are known. As of 2013, the current system has a very narrow "neck" where it folds back on itself. One known previous design uses more metal and appears to be more complicated; this design has been found in the Hirose Cherry MX Orange[3] and Hirose Cherry MX Clear, as well as Cherry MX Black.[4]

All German Cherry MX switches, and some Japanese-made Hirose MX switches, are branded "CHERRY" on the top; the exact logo used has varied over time. Hirose MX switches were also branded "HCP" (Hirose Cherry Precision).

The shell's design is based on the Cherry M9. The upper shell cannot be removed while the switch is mounted in a plate; it must first be de-soldered and removed, as the plate prevents the shell's four retention clips from moving outward. For modification, PCB-mount keyboards are preferred, or enthusiast-created plates with four small cutouts that allow the switches to be opened in-place.

Clicky MX switches use a special two-piece slider with a movable contact that fires the "click collar" downwards on passing the actuation point. When the switch is released, the click collar is pulled back upwards by the slider itself and held in place by the movable contact.

The keycap mount is only 180° rotationally symmetrical. The horizontal (E and W) arms of the cross are around 1.25–1.30 mm thick, while the vertical (N and S) arms are 1.05–1.10 mm thick. Keycaps do not always fit sideways. The stem is around 3.7 mm tall and sits on a platform that descends inside the switch, allowing the full travel to be greater than the stem's height.

Variants

Force-travel diagram (CN/mm) of the downstrokes of the most common Cherry MX switches

Common variants

The most common Cherry MX variants are Black and Red for linear switches; and Clear, Brown and Blue for tactile switches. Keyboards based on the clicky MX Green and tactile MX Grey variants also exist; but due to their heavier resistance, these variants are usually reserved for space bars.

Hirose Cherry

Hirose Cherry Precision ("Cherry Japan") manufactured a version of the MX switch with the Hirose Cherry keycap mount. Hirose Cherry MX switches accept standard Cherry MX keycaps, but Hirose keycaps do not fit standard switches.

Other variants

Some rarer Cherry MX variants have transparent switch housings, and allegedly the earliest MX switches all had clear stems.[5]

Old versions of MX Blue switches exist. Because no dye was added to their stems, these switches are called Whites.[Citation needed]

Observed variants

Country-specific types

Position six in product codes is "1" for a Cherry MX keystem, and a country-specific letter otherwise. The only known example of this is "G" for Germany; these switches are listed by a number of stockists and other sites, but in all cases appear to be false stock levels and no parts are available for sale. Cherry Americas have three of the products on record, as obsolete parts (two of which with meaningful descriptions), and examples of three of the types in their offices (MX1A-1GBR, MX1A-EGEQ and MX1A-1GCL); the remainder of the product codes below remain entirely unconfirmed. The three examples where parts have been retained are all Cherry MX mount, and the only apparent difference in all cases is customisation of the return spring weight.[6]

Product code Source Description MX1A-1GAP Cherry "MX1A-1GAP" [sic] (database record only) MX1A-1GBR Cherry Derived from MX Black, PCB mount, 179 cN according to the database record ("179 CN PCB MOUNT N/O") MX1A-1GCX Cherry "350CN W/PINS" (database record only) MX1A-1GCL Cherry Derived from MX Black; PCB mount; the bag states “lowest force possible”, but it seems to be only slightly lower in force than standard MX Black; the bag is dated 8-26-94 MX1A-EGEQ Cherry Derived from MX Blue; PCB mount, 180 cN MX1A-1GER Surplus sites None MX1A-1GFD Surplus sites None MX1A-1GRE Surplus sites None

Unconfirmed variants

"Cherry MX Yellow" (Aristotle Yellow) is now officially determined to not be a Cherry product. As such, the following switches—not yet sighted in any keyboard at the time of writing—are not verified Cherry products. They are Cherry-branded, but they may be counterfeit.

Recombination variants

There are several custom Cherry MX Switches that can be created by merging together two different switches.

Features (as advertised by Cherry

Desktop profile, 0.60 inch (15.2 mm) from PCB (no keycap)

Choice of feel: linear, soft tactile, click tactile

PCB or frame mount

Long life of 50 million operations (previously also 20 million and 500 thousand depending on model and age)

4 mm travel

LED, diode or jumper option

12V maximum AC/DC

Current Rating: 10 mA

Insulation Resistance: < 100 MΩ at 100V DC

Mounting options

A PCB mountable Cherry MX switch

Comparison between plate and PCB mount switches

Cherry MX switches are available with additional mounting options for either a wire bridge, an LED or a diode.

They are also available for either PCB or plate mounting. Switches for PCB mounting have two additional plastic pins to secure and stabilize them (although plate-mounted switches do not necessarily need these extra pins, as they are stabilized by the metal backplate). PCB-mounted switches can easily be converted for back-plate mounting by cutting off the extra stems.

Mounting designs are specified by the last two digits of the switches' product numbers (see below).

Product numbers

The Cherry MX series follows an eight-digit naming convention: M X [1,3,5] [A,C] - [0-9, A-Z] [1] [N,R,G,Y,D,J] [N,W,A,B]

Examples of Cherry MX product numbers and their descriptions:

MX1A-11NN - Cherry MX Black/linear, no diode, plate mount (no fixing pins)

MX1A-E1DN - Cherry MX Blue/tactile clicky, with diode, plate mount (no fixing pins)

MX1A-L1RW - Cherry MX Red/low-force linear, red LED, PCB mount (with fixing pins)

MX1A-G1JW - Cherry MX Brown/tactile non-clicky, with jumper wire, PCB mount (with fixing pins)

Disassembly

The Cherry MX switch shell is based on Cherry's previous low-profile M9 switch ("low-profile" in the '80s being standard profile from the '90s onward).

The switch has four retention tabs: two on the left and two on the right. A loose switch can be opened by prying these tabs either from the top or from the bottom, and different switch-opening tools exist for either method.

PCB-mounted MX switches can be opened in-place, using their four corner holes: Insert a narrow flat screwdriver into two opposite holes, then pry the side retention tabs away from the switch body.

Most plate-mounted switches must be removed to be opened, as the plate prevents their side tabs from moving outward to clear the retaining lugs. Some DIY keyboard kits have cutouts for the retention tabs, allowing them to be opened in place. Other keyboards, primarily for enthusiasts, have hot-swapping sockets allowing switches to be removed and replaced without de/soldering.

Opening one side of a PCB-mounted switch.

Gallery

Accessories

MX switch with LED fitted

MX switch with jumper fitted

Switches with LEDs fitted require diodes to be external

Design

Base

Front

Rear

Variant design used for windowed keycaps on certain Cherry models such as the G80-3700HAU/04

Hirose Cherry MX switch with original HCP branding

Construction

Sliders and springs

Click sliders from blue and white switches

MX Blue and opened MX Brown

Partially disassembled switch

Gold crosspoints

Electrical contacts, newer design (2013 switch)

Electrical contacts, original design (1984 switch)

Contact plate and leaf (2013 switch)

Fully disassembled MX Brown (top views)

Fully disassembled MX Brown (bottom views)

Classic (left) and revised (right, from 2016) non-silenced slider design

Silencing

To provide damping, Cherry revised the slider to contain an integral, fully moulded-in-place damper. The damped switches use softer colours for the sliders.

"Silent" switch slider designs, with upstroke and downstroke damping using a moulded-in rubber damper

Classic undamped vs damped sliders

Classic undamped vs damped sliders

See also

Cherry MX Series Key Switch on Cherry's home page.

Keymodules on Cherry UK web page.