Alps SKCM Blue
Manufacturer	Alps Electric
Family	Alps SKCM/SKCL series
Part Number	SKCMAG
Switch Type	Clicky
Travel	3.5mm
Sense method	Metal contact
Mount	Plate mount
Rated lifetime	20 million cycles
Quoted operating force	70gf

Alps SKCM Blue is a clicky switch in the first generation of the Alps SKCM/SKCL Series.

The switch follows the general characteristics of the SKCM family, consisting of an upper and lower housing, contact module, stem, spring and a leaf spring for generating the tactile event and click sound.

As a first generation SKCM/SKCL switch, the upper housing always has slits (colloquially referred to as the “pine” variant). Similar to other first generation switches, the only Alps branding on the switch is usually the older Alps logo on the bottom of the lower housing, however, on later switches the upper housing with the newer Alps logo is used.

The stem, which is a dull shade of blue, was lubricated at the factory and is likely made of a nylon blend¹⁾.

The audible feedback is generated with a leaf spring that is situated on the opposite side of the housing to the contact module. There were at least two variations of this leaf spring. Alps SKCM Blue, like all SKCM/SKCL series switches, uses a contact module to register the keypress. This sits in the housing on the side with visible notches.

The switch was likely in production from 1985²⁾ to around 1989. It has been seen with every variation of contact module used in the mainline SKCL/SKCM series, from the original tall black contact module³⁾ to the short white contact module more commonly associated with the second generation of SKCM/SKCL switches⁴⁾. However, tall grey contact modules are most common. Variations in stem dye lots were commonplace and should not be taken as evidence of some instance of the switch being better than another.

The leaf spring that generates the tactile and audible events had at least one revision. The original form of this leaf spring had smaller lateral tabs and no bend at the bottom, as well as appearing visually to be made from a different material. This form is similar but not identical to the leaf found in Alps SKCM Amber. The later form of this leaf spring is indistinguishable from that found in the successor, Alps SKCM White.

In its later form, the switch as a whole is practically indistinguishable from Alps SKCM White. Indeed, there is significant overlap between the two switches with some early Alps SKCM White being factory lubed, which makes them completely identical to the latest Alps SKCM Blue.

There is also a heavier version of this switch, only observed so far in NEC PC-8801 keyboards with an extremely high weighting, marked with black marker on the stem. Given it does not appear to have been seen anywhere else, this is likely a customized switch and not part of the series proper.

There is a purported “pale blue” variant with a very slightly different stem, however no disassembled pictures of the switch have ever been provided and it is impossible to substantiate any potential difference to the rest of the line, or indeed any Alps progeny.