Breaking Down HMX's Latest Mold Improvements: What Keyboard Switch Enthusiasts Need to Know
DashanYuan
In keyboard switches, mold design and the injection molding process do more to determine sound profile and typing feel than most buyers realise. In HMX's case, the molding is a large part of why their switches produce that consolidated, high-pitched, clacky signature.
This is a full history of HMX's mold sets: what each one is, what changed between them, how each affects sound and feel, and — at the end — how to tell them apart just by looking at the parts.
The OG Mold
In use: March 2023 to late November 2023
Switches made with it: Xinhai (early batch), Hyacinth V2/V2U (early batch), Macaron, Macchiato (early batch), Cloud (early batch), Swift (early batch), Cheese
Traits
- Bottom-out: solid and firm
- Sound: high-pitched and loud even with softer materials; some switches can sound thin depending on the plastic. Very clacky overall
- Stem wobble: extremely tight, near zero
- Syringe effect: prominent. The gap between stem and top housing was too small, leaving no room for air movement, so the keystroke felt sluggish
- Leaf ping: none. Very clean sound
- Bottom housing: relatively small
The OG mold is what made HMX's name. The traits above set them apart from every other manufacturer in the game, and the switches were both high quality and cheap — which is exactly the combination that made HMX a community favourite almost overnight.
They were not perfect. The syringe effect was the real complaint, particularly for people sensitive to it, and it traced directly back to the top housing and stem geometry of the time.
The OG Mold 2.0
In use: December 2023 to present
Switches made with it: Xinhai, Hyacinth V2/V2U, Macaron, Macchiato, Cloud, Swift and Cheese (all new batches). Effectively every original HMX switch manufactured after the end of 2023. Some newer releases — Joker, Su Color, Twilight, Guava, Mist — also use OG 2.0.
Traits
- Bottom-out: solid
- Sound: high-pitched and loud, still very clacky; can still read thin with certain materials
- Stem wobble: minimal, but noticeably less tight than the OG mold
- Syringe effect: largely fixed
- Leaf ping: none
- Bottom housing: relatively small
December 2023 was HMX's first real mold revision. They modified the top housing and stem molds to leave a slightly larger gap between the two, giving the stem a little more room to move. Keystroke initiation stopped feeling sluggish and overall travel got smoother. Batches produced after this change improved noticeably.
The New Mold
In use: June 2024 to present
Switches made with it: KD200, FJ400, Game 1989, Yogurt, Swift V2, Martini, Pink Pig, Gulf
Traits
- Bottom-out: solid
- Sound: high-pitched, loud, and distinctly fuller. Still clacky
- Stem wobble: minimal
- Syringe effect: fixed, same as OG 2.0
- Leaf ping: none
- Bottom housing: relatively larger
The clearest demonstration is KD200 versus Cheese: identical material spec, and yet KD200 sounds appreciably fuller. That difference is the mold, not the plastic.
For switches using softer materials — FJ400, Game 1989 — the new mold pushes them quieter and thockier than the old mold would have.
The motivation was differentiation. HMX recognised that a large number of switches coming off the OG mold were landing on very similar sound profiles, so they built a second mold set to widen the range. The enlarged bottom housing is a secondary benefit: switches sit tighter in the plate.
Special-Case Molding
Three switches do not fit neatly into the above:
- HMX Snow Crash — OG 2.0 housing with an entirely new rail bottom-out stem mold
- HMX Guava — OG 2.0 housing with a new HDPE stem mold
- HMX Mist — OG 2.0 housing with a new H1 stem mold
The Leaf Ping Episode
For a stretch, new HMX releases and restocks arrived with notorious leaf ping. This affected everything released between roughly May 2024 and July 2024 — Gachapon, Ice Cendols, Su Color R1, and the May restock of Macchiato among them.
The cause: HMX changed leaf supplier in April 2024. The new leaves had design flaws that did not work with HMX's molding geometry, and no amount of adjustment to the factory lubing process could mask it. After exhausting the alternatives, HMX concluded the leaf itself was the root cause and reverted to the original supplier in July 2024.
Every HMX switch and restock produced after July 2024 is free of the problem. If you are buying HMX today, this is history, not a live risk.
How to Tell the Molds Apart Visually
Stem — internal circle
The new stem mold has an internal circle for better spring positioning. The OG and OG 2.0 stems do not.
Stem — rail gap
New stems have a rail gap, visible on the green stem below. OG and OG 2.0 stems do not.
Bottom housing — number marking position
This is the easiest tell. The new bottom housing puts its number marking above the stem legs. OG and OG 2.0 put it between the switch pins.
Top housing
The differences are too small to perceive by eye. Use the stem or bottom housing instead.
So Which Mold Is Better?
Neither. HMX runs two active mold sets — OG 2.0 and the New Mold — and both are refined. They are different, not ranked.
The simple version:
- If you like the classic HMX sound — high-pitched, loud, sometimes thin — buy switches on the OG 2.0 mold.
- If you want that same loud, clacky character but fuller, buy switches on the New Mold.
Browse the current lineup in our HMX switches collection, or compare against the wider keyboard switches range.