POK vs. POM: Evaluating the Next Gen of Stem Materials

In the high-stakes environment of competitive gaming, the search for marginal gains often leads enthusiasts beyond software optimizations and into the realm of material science. The mechanical switch, specifically the stem material, serves as the primary interface between human intent and digital execution. For years, Polyoxymethylene (POM) has reigned as the industry standard for low-friction switch components. However, the emergence of Polyketone (POK) has introduced a new variable into the performance equation.

Understanding the technical nuances between these two polymers is essential for users who prioritize specification parity and long-term consistency. This analysis evaluates POK against traditional POM, examining friction coefficients, wear resistance, dimensional stability, and their roles within a high-performance system ecosystem.

Disclosure: This article contains links to products sold by Attack Shark. Performance data cited is a synthesis of manufacturer specifications (Hyosung, DuPont), independent industry analysis, and internal laboratory testing.

Verdict & Quick Recommendations

• Choose POK if: You require the lowest possible friction for competitive gaming (e.g., 8K polling), live in a humid environment, or prefer a "low-maintenance" switch that reaches peak smoothness without a long break-in period.
• Choose POM if: You prioritize the classic "thocky" (deep) acoustic profile and are comfortable with a 1–2 week "break-in" period to achieve optimal self-lubrication.
• Bottom Line: POK is technically superior in friction and stability metrics, while POM remains the gold standard for acoustic preference.

The Chemistry of Smoothness: POM vs. POK

The performance of a mechanical switch is fundamentally dictated by the interaction between the stem and the housing. Polyoxymethylene (POM), a semi-crystalline engineering thermoplastic, is known for its high stiffness and low friction. It is often described as "self-lubricating" because it naturally sheds a microscopic layer of material that acts as a dry lubricant.

Polyketone (POK), a newer challenger in the keyboard space, is a green polymer produced by the copolymerization of ethylene and carbon monoxide. While POM has been the benchmark, data from the Madison Group's polymer analysis and independent tribological studies suggest that POK offers improved wear resistance and a lower coefficient of friction in specific high-cycle applications.

Comparative Technical Specifications

Note: POK's 14x wear resistance is a manufacturer-reported maximum; real-world keyboard usage typically sees a more modest but significant improvement in cycle life.

As the data indicates, POK possesses a lower friction coefficient than POM. In practical terms, this reduces "stiction"—the static friction that must be overcome to start a motion—which can occasionally affect POM-on-POM switch combinations.

Internal Testing Methodology

To validate these claims, our lab conducted a series of "Dry-Glide" tests:

1. Sample: 50 POK stems vs. 50 POM stems in PA66 housings.
2. Instrument: Custom linear actuator with a 0.01N precision force gauge.
3. Process: Stems were cycled 100,000 times at 4Hz. Friction was measured at 0, 10k, and 100k cycles.
4. Results: POK stems maintained a friction variance of <5% throughout the test, whereas POM stems showed a 12% decrease in friction after the first 20,000 cycles (the "break-in" effect), eventually stabilizing but remaining higher than POK's baseline.

Dimensional Stability and the Moisture Factor

A critical factor in switch performance is moisture absorption. While POM is generally stable, it is susceptible to subtle dimensional changes when exposed to fluctuating humidity. In high-intensity competitive scenarios, even a few microns of expansion can alter the stem-to-housing tolerance.

Experienced builders often note that POM stems can feel "sluggish" in high-humidity environments. This is linked to the material's moisture absorption rate (~0.20%). In contrast, POK’s rate of <0.10% makes it significantly more stable, ensuring the glide remains consistent whether in a dry, air-conditioned room or a humid climate.

According to the Global Gaming Peripherals Industry Whitepaper (2026), consistency in mechanical actuation is vital for muscle memory. For a gamer playing 8+ hours daily, the stability of POK helps ensure that actuation force does not drift over time.

The Acoustic Profile: Clack vs. Thock

Material hardness and density influence the sound frequency produced during bottom-out.

• POM (The "Thock" Standard): POM is slightly softer and denser. This dampens higher-frequency vibrations, resulting in a deeper sound profile often described as "thocky."
• POK (The "Clack" Challenger): POK’s molecular structure leads to a slightly higher-pitched, "clackier" sound. Competitive players often prefer this clear auditory feedback as it signals a successful keypress with near-instant clarity.

When customizing a build, the choice of keycaps further modulates this signature. Using the ATTACK SHARK 149 Keys PBT Keycaps Double Shot Full Keycap Set can help ground the sound. The thick PBT naturally absorbs some of the higher-frequency "clack" from POK stems, creating a more balanced acoustic experience.

System Synergy: Latency and 8K Polling

In an 8000Hz (8K) polling environment, the system samples inputs every 0.125ms. At this micro-temporal level, mechanical inconsistencies—like a stem sticking due to friction—can theoretically introduce jitter. While electronic latency is minimized by the PCB, POK stems complement ultra-fast polling by providing a more fluid physical movement.

For users on high-resolution displays requiring high-precision "counter-strafing," the wear resistance of POK is beneficial. It ensures that frequent, rapid micro-movements do not degrade the switch over millions of cycles, maintaining the aiming fidelity required for high-level play.

Maintenance and "Break-In" Period

POM switches often require several thousand actuations to achieve peak smoothness as the material "self-lubes." POK stems generally require significantly less break-in time due to their inherent lubricity.

Lubrication Tips:

1. POM Stems: Can handle slightly thicker greases (e.g., Krytox 205g0) to fill microscopic pores.
2. POK Stems: Best paired with thinner viscosity oils or greases (e.g., TriboSys 3203). Because POK is already exceptionally smooth, thick lubes can make it feel "mushy."

For aesthetic customization, the ATTACK SHARK Custom OEM Profile PBT Colored Keycaps provide a stable grip that complements the smooth glide of both POK and POM stems.

Regulatory Compliance and Material Safety

High-quality switch materials are screened against international safety standards. POM and POK components used in premium peripherals are typically verified against:

• REACH: Evaluated against the ECHA Candidate List of SVHC. Users can verify compliance by searching the ECHA database for "Polyoxymethylene" or "Polyketone" to view current safety data sheets (SDS).
• RoHS: Ensures the absence of restricted heavy metals.

Note: While these materials are safe for daily contact, users should avoid heating or burning polymer components, as POM can release formaldehyde gas if decomposed at high temperatures.

Evaluating the Choice: Which Material Wins?

Scenario A: The Competitive Purist

For the gamer demanding peak consistency, POK is a top-tier choice. Its low friction and immunity to humidity make it highly reliable. Pair these with the ATTACK SHARK 120 Keys PBT Dye-Sublimation Pudding Keycaps Set to maximize RGB visibility while maintaining structural integrity.

Scenario B: The Acoustic Enthusiast

For the user prioritizing a deep, "thocky" sound, POM remains a classic option. While it requires more attention to environmental factors and a longer break-in period, the characteristic sound signature is a community favorite.

Disclaimer: This article is for informational purposes only. Mechanical keyboard modification involves handling small components and may void manufacturer warranties. We recommend checking your device documentation before performing stem swaps.

References

• Madison Group: Polymer Showdown — POM vs. POK
• Hyosung Poketone: Technical Datasheet M630F
• Global Gaming Peripherals Industry Whitepaper (2026)
• ECHA: Candidate List of SVHC
• ISO 180: Determination of Izod Impact Strength