haimu Sea Salt Linear Switches

The Haimu Seasalt is a linear mechanical switch designed for custom keyboard users who want a smooth, quiet typing experience without tactile bumps or audible clicks. It suits those who prefer a moderate actuation force and a clean keystroke feel, making it a reasonable choice for both typing and gaming. Its factory lubrication reduces the need for immediate modification, appealing to users seeking ready-to-use switches with consistent performance.

Feel & Sound

The switch offers a smooth, linear keystroke without tactile feedback or click noise. Its factory lubrication helps minimize scratchiness and produces a quieter sound profile. Bottoming out feels moderate in firmness, which can reduce finger fatigue during extended typing sessions. The sound is generally subdued, making it suitable for quieter environments.

Actuation Characteristics

With an actuation force around 47 gf and a pre-travel of about 2.0 mm, it requires moderate pressure to register a keypress. The total travel distance of approximately 3.6 to 4.0 mm provides a standard key travel length, balancing responsiveness and comfort. The dual-stage spring design may influence the force curve subtly, but the switch remains linear throughout the press.

Build Quality

The top housing is made of transparent polycarbonate, which supports good RGB lighting diffusion. The bottom housing uses nylon, contributing to durability and sound dampening. The stem is constructed from POM, a low-friction material that complements the pre-applied lubrication for smooth key travel. The dual-stage spring is relatively long at 22 mm, which can affect the switch’s overall feel and sound.

Compatibility

The switch features a 5-pin MX-compatible PCB mount, ensuring compatibility with a wide range of custom keyboard PCBs. Its transparent housing allows for effective RGB lighting, enhancing visual customization. It is not specified whether the switch supports hot-swap sockets, so compatibility with hot-swap boards is unknown.

Trade-offs

While factory lubrication reduces initial scratchiness, some users may still prefer additional lubing or filming for further smoothness and noise reduction. The dual-stage spring design is uncommon and may not suit users expecting a traditional linear force curve. The switch’s moderate bottom-out force could feel less cushioned compared to heavier or more specialized switches. Stem wobble and spring ping are unknown.