Aluminum, polycarbonate and ABS describe keyboard case materials. Polycarbonate and ABS are both plastics; naming the polymer is more informative than treating all plastic cases as one category.
Material properties can help explain density and structural differences. They do not establish how a finished keyboard sounds, feels or performs. This guide separates the cited material data from the additional specifications needed for a buying decision.
Identify the whole enclosure
Check whether a product description refers to the top case, bottom case, outer frame or switch plate. A board can combine materials, so a metal top does not mean the whole enclosure is metal.
Record the parts separately rather than treating a mixed-material case as if it belongs entirely to one category. The plate and the mounting arrangement are distinct from the outer case.
What the cited material data supports
The linked MatWeb record concerns a particular polycarbonate material, and the two data sheets cover 6063-T6 aluminum and ABS. They provide material properties, not measurements of a keyboard built from those materials.
| Material | Information available here | What to check on a keyboard listing |
|---|---|---|
| Aluminum, 6063-T6 example | Density of approximately 2.7 g/cm³ in the cited material data | Exact alloy, case components, dimensions and assembled weight |
| Polycarbonate | Density of approximately 1.2 g/cm³ in the cited material data | Polymer specification, wall geometry, case components and assembled weight |
| ABS plastic | Density of approximately 1.06 g/cm³ in the cited data sheet | Exact material, case components and assembled weight rather than borrowing PC’s figures |
Sources: MatWeb polycarbonate data, the 6063-T6 aluminum data sheet and the Xometry ABS data sheet.
The density comparison applies to equal volumes of those materials. Finished boards are a different question, because wall thickness, internal geometry and the other parts all add weight; the next section gives three makers’ published assembled weights.
The cited alloy and polymer data also should not be applied indiscriminately to every product labeled aluminum or PC. A product page that omits its precise material specification leaves that detail unresolved.
Published assembled weights for three boards
Each maker below publishes an assembled weight for a named configuration, and their cases use the three materials this guide compares.
| Board | Case as listed by the maker | Published assembled weight | Layout and other weight |
|---|---|---|---|
| Keychron V1 | ABS plastic, tray mount | 970 g ± 10 g (fully assembled version) | 75%, steel plate |
| KBDfans Tofu65 2.0 PC kit | Polycarbonate | About 1.2 kg after assembly | 65%, titanium weight bar in the kit |
| Keychron Q1 Version 2 | Full CNC-machined aluminum, gasket mount | 1825 g ± 10 g (fully assembled version) | 75%, steel plate |
These compare finished products, not materials. The Tofu65 is the smallest layout here and its kit adds a titanium weight bar, so its weight is not a polycarbonate figure on its own. The two Keychrons are the closer pair: same maker, same 75% layout, both with a steel plate. The aluminum Q1 weighs almost twice as much as the ABS V1 (1825 g against 970 g). The density gap points the same way, but the case design decides the actual number.
Case material does not establish a sound ranking
An aluminum label does not prove a higher-pitched or cleaner sound. A polycarbonate label does not prove a deeper sound. ABS does not automatically mean a hollow-sounding board.
Those descriptions concern a complete assembly and listening conditions. The material records cited here contain no keyboard acoustic measurements, so they cannot support those rankings.
When comparing construction, record the enclosure geometry, mounting arrangement and any documented damping materials. That produces a useful parts comparison without claiming that a particular combination guarantees a sound.
Foam is another specification to check, not a universal equalizer or evidence that one material will remain brighter than another. Its presence alone is insufficient to rank finished boards.
Stiffness data is not a typing test
Bulk material stiffness and movement at a key are different questions. A case’s shape and its connection to the plate and PCB matter alongside the material.
The cited material data does not measure the displacement of a key, the movement of a plate or a person’s perception of bottom-out. It therefore cannot establish that every aluminum board is firm, every PC board is bouncy, or every thin ABS case rattles.
Read the manufacturer’s assembly diagram together with the material list. A listing without deflection figures cannot tell you how much the case flexes.
Weight, portability and cost
For a keyboard you intend to carry, compare assembled weight and dimensions. Do not infer them from a photograph or a material name. A higher density for the same volume does not tell you the volume used in two differently designed cases.
For a keyboard that stays on a desk, decide whether the listed weight meets your preference. Weight alone does not establish build quality, resistance to sliding or durability.
Cost is also a separate buying constraint. Our mechanical keyboard budget tiers guide explains how to compare included parts without turning a price tier into a sensory ranking.
A practical buying sequence
- Choose a keyboard size with the key clusters you need.
- Choose the switch family and compatible switch options.
- Decide whether hot-swap or soldered construction fits your replacement plans.
- Compare case components, plate, mounting arrangement, assembled weight and included damping on the exact configurations.
Stabilizers and keycaps remain separate parts of that comparison. Their specifications should not be inferred from the case material.
Use the side-by-side comparator to identify stored differences, then check the manufacturer’s documentation. A useful case recommendation names a documented requirement it satisfies; it does not promise a premium sound from the material alone.
