Editing Tactility (section)

===Obstructing metal leaf===
{{Main|Click leaf}}

An obstructing metal leaf is a [[leaf spring]] bearing kinks that obstruct the passage of the [[slider]]. In order for the slider to pass the leaf spring, the leaf spring must be deflected out of the way; the kinks in the metal cause the slider to catch on the leaf spring, requiring a sharp increase in force to clear the obstruction.

This leaf spring can be a dedicated part, one of the switch contacts, or the actuator leaf. [[Alps SKCM Brown]] and [[Omron B3G-S White Tactile]] in particular use a modified actuator leaf placed on the opposite side of the slider. Some [[Mitsumi standard mechanical]] switches have a kinked actuator leaf instead, while [[Siemens STB]] switches use the switch contacts as the tactile leaf.

<gallery widths=250 heights=187>
File:Omron B3G-S white tactile -- actuator and tactile leaves, top.jpg    | Omron B3G-S White Tactile actuator and tactile leaves
File:Omron B3G-S white tactile -- actuator and tactile leaves, bottom.jpg | Omron B3G-S White Tactile actuator and tactile leaves
File:Mitsumi std -- leaf comparison.jpg                                   | Mitsumi standard mechanical standard and tactile switchplates
</gallery>

This approach may optionally provide audible feedback. If the leaf is folded back against itself, and allowed to be pulled forwards and released by the slider, a sound is generated as the spring snaps back into its rest position. A leaf spring in this configuration is called a '''click leaf'''.

The effectiveness of tactile leaves is debatable. The most successful non-audible implementations appear to be [[Alps SKCM Orange]], [[Alps SKCM Brown]], [[Alps SKCM Green]] and [[SMK second generation]]. When a click sound is permitted, the tactile feel is always sharpened and strengthened. A compromise implementation is [[Alps SKFS White]], which uses a click leaf but has an empty space behind it to prevent impact occurring when the leaf is released; this gives a stronger tactile response without the accompanying sound.

The official force curves for 1994 Alps switches depict the difference between Alps SKCM Green and all other types of SKCM (tactile) switches, showing how the force curve of green differs:

[[File:Force graph--Alps tactile 1994.svg|centre]]

The force curve of Alps SKCM Brown is confirmed to be the same as what Alps depicted for Alps SKCM Green.<ref name="plotly_brown" />