What is the difference between actuation force and bottom-out force?

Actuation (initial/operating) force is what it takes to reach the trigger point; bottom-out force is what it takes to press the stem fully down. Bottom-out is always higher.

What does pre-travel mean?

The distance the stem moves before actuation. On a Cherry MX-style switch it is about 2 mm of the 4 mm total travel.

Does a higher bottom-out force mean a stiffer switch?

Generally yes — it tracks spring weight — but housing friction, lube and stem design also shift the feel, so compare force curves rather than one number.

How to read switch specs

Every number on a switch listing, decoded — with the traps that make listings look more different than they are.

The two travels: actuation and total

A switch's vertical journey has three landmarks:

Pre-travel / actuation distance — how far the stem moves before the keypress registers. Cherry MX-class: ~2.0 mm; speed switches: 1.1–1.5 mm. HE magnetic: you choose it (0.1 mm+).
Tactile event (tactile/clicky only) — the bump or click, usually placed at or just after actuation.
Bottom-out / total travel — the floor. MX-class: ~4.0 mm; silent variants shorten it (~3.7 mm) with damping pads; low-profile Choc ~2.8 mm.

Trap: "operating force" listings sometimes quote the force at the tactile event, not at actuation. Compare within the same brand family, or read force curves.

The two forces: initial and bottom-out

Term	Also called	Meaning	Typical
Initial / actuation force	operating force, trigger force	Force needed to reach the actuation point	45 cN (light) … 65+ cN (heavy)
Bottom-out force	max force	Force at full travel	≈ actuation +15–25 cN

cN vs gf: 1 cN ≈ 1.02 gf — listings use them interchangeably; treat 45 cN and 45 g as the same. Trap: HE listings quote spring weight (start/bottom-out), not a trigger force, because trigger depth is user-set.

Rule of thumb for feel: light linear (40–50 cN) for long sessions, 55–62 cN "creamy" mid-weights for typing, 65+ for deliberate typists. Tactile switches feel stronger than their number because the bump adds resistance early.

Reading a force curve

Force-travel plots show force (y) over travel (x):

Linear — a rising slope. Steeper = heavier; a flat start = light initial force.
Tactile — a bump at the tactile event, then a dip (the "snap"), then rise to bottom-out. Bigger bump = more pronounced tactility.
Clicky — a sharp spike and drop at the click.

Our database draws stylized curves per switch (from act/total/force values) — good for comparing shape and weight at a glance, not a substitute for measured lab curves (see thoc.club-style measurement databases for lab data).

Tactility terms

Term	Meaning	Examples
Pronounced / sharp bump	Distinct, high-contrast tactile event	MX Clear, Boba U4T, Box Royal
Rounded / medium bump	Gentle, "brown-class" feedback	MX Brown, Gateron Brown
Long-pole	Longer stem pole → earlier bottom-out feel, muted sound	Ink V2 style designs
Click jacket / click bar	Mechanism of the click (jacket = Cherry-style, bar = Kailh Box-style sharper)	MX Blue vs Box Jade

Sound vocabulary

Thock — deep, rounded bottom-out (good case damping + POM/nylon parts). Clack — higher, crisper, more top-end. Creamy — smooth mid-frequency, no harshness. Poppy — short, bouncy, high-pitched pop. Marbly — subtle rolling texture (Oil King-style). Deep/muted — bass-dominant, quiet (Ink, silent switches). Sound depends at least as much on plate, case, mounting and keycap as on the switch itself — the same switch thocks in a gasket aluminum board and clacks in a tray-mount plastic one.

Physical & mounting specs

Pins: 5-pin (PCB mount, two extra legs for alignment) vs 3-pin (plate mount). 5-pin works in 3-pin sockets after clipping; 3-pin in 5-pin sockets is fine.
Stem: MX cross 4.1 mm standard — see the keycap rules for the exceptions (Choc, Alps, Topre, HE variants).
LED slot: south-facing = LED under the stem (better shine-through from the user's angle); north-facing = LED behind the stem (can clash with shine-through caps on some boards).
Mounting style of the board: gasket/PCB sandwich feels softer and deeper; tray-mount is stiffer and higher-pitched. Same switch, different sound.
Factory lube / films: improve smoothness and reduce spring noise; "hand-lubed" community mods go further.

Putting it together

When comparing two switches in our database: match total travel first (feel of the floor), then bottom-out (weight), then tactility and sound. Two switches with identical numbers can still differ — spring shape (progressive vs linear), stem material (POM vs nylon) and housing tolerances dominate real-world feel. Treat all figures as ±10%.