Glossary of terms used on this site
Defining all of the major mechanical keyboard terminology, technology, and specifications.
Terms such as "linear," "tactile," and "clicky" refer to how a switch feels or sounds when actuated.
The depth at which a switch will register a keystroke, usually measured in millimeters. For example, Cherry MX Brown switches have an actuation depth of 2mm. When such a key is depressed 2mm, the key will activate and electrically input the keystroke. Romer G switches have a shallower actuation depth of 1.5mm; this means they “trigger” at a shorter distance than MX Brown switches.
Alps switches are interesting in that they are no longer officially produced, but clones exist. Hua-Jie, Kwanda, Tai-Hao, Xiang Min, Gaote, and some unknown manufacturers have all produced or continue to produce Alps clones. Alps switches function similar to Cherry MX/Kailh switches in terms of how they actuate, but one difference is that Alps switches use a metal leaf as the contact mechanism.
|Buckling Spring Switches||
There were many different switch types used in the early days of computers, but buckling spring switches were very common. Buckling springs have springs which are depressed until they "buckle" and complete a circuit, this makes them loud and tactile.
|Cherry MX Switches||
Cherry MX switches are some of the most common mechanical switches today. It should be noted that Kailh also manufactures Razer Switches and Cherry clones. All Cherry & Kailh switches use a spring in conjunction with a stem that lowers when pressed. When pressed, the stem pushes two contacts to touch, completing a circuit.
Hysteresis is a term used to describe the input gap between the actuation point and reset point. Most switch reset points are shallower than the actuation depth (higher up), so a key has to be released almost fully in order to reset for the next press in most instances.
Hysteresis can make double-tapping and rapid same-key typing difficult, so there's a trade-off in function.
Cherry MX & Kailh switches are some of the most common mechanical switches today. It should be noted that Kailh also manufactures Razer Switches and Cherry clones. All Cherry & Kailh switches use a spring in conjunction with a stem that lowers when pressed. When pressed, the stem pushes two contacts to touch, completing a circuit.
Mechanical keyboards must have switches mounted to something, whether that's a PCB, metal plate, or plastic plate. Metal plate mounting is generally found in more expensive keyboards and provides a heavier and sturdier keyboard. PCB mounted switches are found in cheap keyboards and will have more flex and give to them, but they are lighter and cheaper. Plastic plate mounting provides a middle ground between PCB and metal plate mounting, but it’s not commonly used.
|Keyboard Sizes (%)||
Keyboard Size -- Oftentimes referred to in percentages. A standard, full-sized keyboard usually has 104 keys and is considered to be a 100% keyboard. Most designs fall between the range of 80% (TKL) to 40% keyboards. 100%, ~80%, 75%, 60%, and 40% designs are the most prominent, but other sizes do exist.
Mechanical switches have stems that allow for aftermarket keycaps to be installed. Replaceable keycaps allow for novelty keycaps, full keycap set replacement, and general customization of keyboards without doing irreversible modding.
Keycaps are usually made out of ABS or PBT plastics, but can be made out of almost anything. ABS plastic is most commonly used, and is soft compared to many other plastics. ABS plastic has a low melting point, and if placed in boiling water, will warp/melt rapidly. PBT plastic is tougher and more brittle than ABS and has a sandier/grittier feel, but is also less commonly used. PBT also has a high melting point, so they can be boiled without problems. PBT is more expensive to manufacture, so it is less commonly used. Other materials such as heavy metal keycaps, POM (another plastic), and wood are used, but less commonly.
Multimedia controls refer to media (movies, music, etc.) controls that are integrated into keyboards. This can include, but is not limited to, volume control, skipping, play/pause, and stop buttons. This is oftentimes done via a function key, with the controls on the F keys (often Fn+F1-F4).
N-Key Rollover (N-KEY) -- The ability for a keyboard to recognize any number of keys being actuated at once. Whereas a keyboard with 5-key rollover could only detect 5 keys being pressed at one time, in this case, “N” is indicative of any reasonable integer since there is no-key rollover. N-key rollover is sometimes referred to as anti-ghosting.
Repeat Acceleration -- The rate at which a letter repeats when a key is held down. Some keyboards may type 5 letters if a switch is held down for a second, whereas another may type 10. Many keyboards allow for this to be adjusted. Higher repeat acceleration allows for more rapid repeats of text, potentially enabling better "chat-spamming" ability.
|Romer G Switches||
Romer G switches were invented by Logitech for their 2014 Orion Spark G910 mechanical keyboard. We first looked at the Romer G switches at PAX Prime before later reviewing their initial launch in the Orion Spark RGB keyboard. Romer G switches are designed to actuate and feel similar to damped Cherry MX Browns; they're quiet, have a shallow actuation depth, and have altered design to allow for better backlight spread (less bleed) and more vibrant LEDs.