|This article requires illustration in the form of diagrams — Would be nice to have diagrams of each mount with dimensions|
- 1 Integrated mounts
- 2 Snap-on mounts
- 3 Cherry MX mount
- 4 Hirose Cherry mount
- 5 Custom cruciform
- 6 Tee and bar mount
- 7 Alps mount
- 8 IBM Beam Spring / Selectric mount
- 9 RAFI mount
- 10 Mitsumi mount
- 11 Key Tronic mount
- 12 Topre mount
- 13 Clare-Pendar mount
- 14 Marquardt mount
- 15 References
A mount is "integrated" when the bottom part of the keycap is the switch mechanism's primary slider. Integrated mount is not a standard: integrated mount keyboards are not incompatible with each other.
- The majority of full-travel rubber dome keyboards. The exceptions are few.
- IBM buckling spring keyboards without "two-piece" keycaps, and non-alphanumeric keycaps on two-piece keycap boards
- IBM Model M2
Dell integrated mount rubber dome keycaps
Snap-on mounts have flat-topped sliders onto which the keycap is affixed. Snap-on mounts are all proprietary and are not compatible between keyboard types.
So-called "two-piece" IBM buckling spring keycaps (snap-on keycap over a stem, or slider)
Fujitsu Peerless slider and keycap
Alps ultra low profile keycaps
Hi-Tek Series 725 keycaps
Cherry MX mount
A cross-shaped stem on the switch's slider into a cross-shaped hole within a cylindrical stem in the bottom of the keycap. This is often called a "Cherry MX mount" because it is found on Cherry MX switches. Whether the mount type has an industry-wide designation is unknown.
Cherry's MX keycap specifications give the keycap slot dimensions as a cross 4.1+0.05 mm wide, with arms 1.17±0.02 mm wide (this would make them 1.465 mm long). There are no known specifications for the switch stem.
Signature Plastics gives the dimensions (presumably of the keycap) as a cross 0.159ʺ (4.04 mm) wide, with arms 0.047ʺ (1.19 mm) wide.
Cherry M8 switches use a cruciform mount with the same lateral dimensions as MX switches, but with a shorter switch stem. This shorter stem leads to keycap incompatibility. Cherry produced a Cherry MX-M8 Adapter variant of the Cherry MX switch family which allowed the use of shorter M8 keycaps on otherwise standard MX switches.
- Cherry MX
- Cherry MY
- Marquardt Series 6184
- Some Mitsumi miniature mechanical switches
- Cherry MX clone switches
- Some Futaba clicky switches
- Some Gateway keyboards, including early Gateway AnyKey, Model no 2189013-XX-XXX
- BTC Dome with Slider
... and more
Keycap manufacturers and vendors
Additional keycaps are made/sold by:
- Signature Plastics
- WASD Keyboards
- Tipro (low profile and relegendable)
- Jarltech (low profile and relegendable)
- Genovation (low profile and relegendable)
... and more
There are also some mount types that are quite similar but not exact like the Cherry MX mount. There are switches with a cylinder around the stem, and there are keys with struts in-between the keycap stem and keycap wall that make it not "Cherry compatible" without modification.
Hirose Cherry mount
Hirose Cherry mount is a smaller cross than Cherry MX mount. Cherry MX keycaps will fit on Hirose Cherry switches, but Hirose Cherry keycaps will not fit on Cherry MX mount keycaps. The horizontal arms are shorter but approximately the same thickness, but the vertical arms of the cross are noticeably thinner, and keycaps made for this mount won't fit onto a Cherry MX mount keycap.
There are many keycap mounts that look very similar to Cherry MX mount, but have incompatible dimensions. They will not take Cherry MX keycaps. Such mounts include those of Cherry M6 and Cherry M7 switches. The slider dimensions are not always 90° rotationally symmetrical: one pair of cross arms may be thicker than the perpendicular pair of arms.
Tee and bar mount
Numerous switch types have tee (⊢) and bar (|) mount sliders. Such switches typically take cross-mount keycaps, and as such, the switches support full 90° rotational symmetry. For example, the Alps SKCC series switch has been found mounted in several orientations, without affecting keycap fit.
A type of mount that is very common for different types of switches. The slider has a slot that is around 4.6 mm × 2.3 mm at the top; the keycap has rectangular peg around 4.5 × 2.2 mm. It is used on various Alps switches including the Alps SKCL/SKCM series, and is therefore most often called "Alps mount". The term "Alps mount" does not mean that all Alps switches used this mount: some switches use similar but incompatible mounts, and many more use use totally different mounts. There are more switch types from third parties that use this mount than there are in Alps Electric's entire product range.
Whether there is an industry-wide designation for this type of keycap mount is unknown.
See keyboard switches with Alps mount. Most notable switches:
See keyboards with Alps switches for keyboards with the Alps and Alps clone switches.
Rubber dome keyboards:
- Monterey K208 (rubber dome keyboard)
- Smartboard rubber dome keyboards
Keycap manufacturers and vendors
Additional keycaps can be purchased from:
IBM Beam Spring / Selectric mount
The slider has a cubical top with an edge length of 5 mm, underneath of wich are two tiny lugs on opposite sites. The keycap has a mating square hole and recesses where the lugs engage when the keycap is snapped on the slider. RAFI described the mechanism in a patent from 1975, GB 1533154 , but did not put any claims on it.
- All of the RAFI RS family
- Siemens STB
- Sasse 200MN
- Low-profile variant of the ITW magnetic valve switch
Key Tronic mount
Sliders are cylindrical and hollow with a bar inside. Each keycap has two fingers that snap onto the bar.
Most often these are Key Tronic foam and foil switches with a rubber sleeve or coiled spring around the slider, but the mount type is also found in keyboards from Alphameric with different switches.
Used on Marquardt's electric typewriter switches. The mount provides two plastic prongs, each approximately 1 mm × 2.5 mm in cross section and around 4.9 mm tall, with a 1 mm gap between them.
- File:Cherry MX 1×1 keycap specification (1983).pdf
- Deskthority thread Telex Keyboard?. Posted 2014-04-05.