The screen protector hardness scale, typically referenced by the Mohs scale of mineral hardness, quantifies a material's resistance to scratches by harder substances. Higher ratings indicate greater durability against everyday abrasives like sand and keys.
The Mohs Scale & Screen Protectors
Mohs Scale Basics: This scale ranges from 1 (softest, like talc) to 10 (hardest, diamond). Screen protectors primarily use synthetic materials aiming to resist common scratches.
Common Hardness Ratings Explained
- Below 6H: Offers minimal scratch protection, suitable only against very soft objects (plastics, some wood). Not recommended for modern devices.
- 6H-7H: Provides basic protection against softer metals like brass and aluminum found in keys or coins. Common for older, cheaper PET film protectors.
- 8H-9H (Most Prevalent): Standard for quality tempered glass protectors. Resists scratches from materials like quartz/sand (Mohs ~7), iron, steel nails.
- 10H/11H Claims: Often represent internal industry scratch tests or Vickers hardness, not Mohs hardness over 9. Marketing terms signaling high resistance, equivalent to real Mohs ~8-9.
Understanding "9H"
9H indicates the protector's surface resists scratches from a standard "9H" pencil lead hardness (a material testing reference point). This correlates roughly with resisting quartz/sand abrasives (Mohs ~7). It does not mean diamond-level hardness (Mohs 10).
Critical Limitations
- Hardness ≠ Impact Protection: A 9H protector can shatter from drops regardless of scratch resistance.
- Edge Integrity: Poor installation or low-quality glass can chip or crack edges easily.
- Coating Matters: The oleophobic coating prevents fingerprints but wears faster than the underlying glass.
- False "Diamond" Claims: No mainstream protector reaches actual Mohs hardness 10 (diamond). Materials like sapphire glass approach Mohs 9.
Practical Guidance
- Opt for 9H Tempered Glass: This provides effective scratch resistance against the most common daily hazards (sand, grit, keys).
- Ignore "11H" Mohs Claims: Focus on the "9H" industry standard for scratch testing.
- Prioritize Reputable Brands: Quality manufacturing and coatings are as crucial as the hardness rating.
- Understand Trade-offs: Extreme hardness claims might indicate brittleness. Balance scratch resistance with impact protection (if advertised).
In summary, the 9H rating signifies robust scratch protection sufficient for everyday use on consumer devices. Prioritize verified 9H tempered glass from reputable manufacturers for reliable screen protection.
