Put an End to False Labeling! National Standards for Tempered Glass Films Officially Implemented in 2026, Three Core Indicators Regulate the Entire Industry

On March 1, 2026, JC/T 2921-2025 Chemical Tempered Glass Protective Films for Screens — China's first mandatory standard for glass protective films in the building materials industry — came into full force. Meanwhile, the association standard T/GDEDIA 0005—2024 General Technical Requirements for Tempered Glass Films has been rolled out nationwide. The consumer electronics screen protective film industry has bid farewell to years of unregulated development, marked by the absence of unified quantitative standards and rampant false parameter claims by sellers.

The new standards set three mandatory baseline requirements: qualified tempered glass films shall have a Mohs hardness of no less than 9H, a visible light transmittance of no less than 90%, and a haze of no more than 1.5%. Dozens of testing specifications have also been updated, covering impact resistance, oil repellency and wear resistance, adhesive layer safety, dimensional tolerance, temperature resistance and yellowing resistance. A full-range regulation system covering raw materials, production processes and finished product inspection has been established, exerting far-reaching impacts on the entire industrial chain including upstream glass material suppliers, midstream processing manufacturers, downstream brands and retailers, as well as end consumers.

I. Background of the Standards: Widespread False Labeling and Uneven Product Quality in the Industry

Over the past decade, with the popularization of smartphones, tablets, foldable devices and vehicle-mounted large screens, the domestic market size of screen protective films has exceeded 42 billion RMB. Thanks to excellent protection performance, tempered glass films hold a 27% market share. The daily penetration rate of screen films for smartphones reaches 92%, making them a must-have accessory for consumer electronics. Despite rapid market expansion, the industry has long lacked unified and authoritative testing standards, leading to various irregularities.

First, false promotion of hardness indicators is prevalent. Numerous low-cost unbranded products are arbitrarily labeled as "10H, 12H Ultra-hard & Shatterproof". Merchants often confuse two different testing systems: pencil hardness and Mohs mineral hardness. Many low-end films made of soda-lime glass claim to be 9H hard, while their actual Mohs hardness is only 5 to 6. They are easily scratched by quartz sand particles (Mohs hardness 7), failing to deliver the claimed protection performance.

Second, optical performance varies greatly, and inferior films damage both screens and users' eyes. Products manufactured by many small factories have a light transmittance below 85% and a haze above 3%. After application, the screen looks dim with reduced contrast, causing visual fatigue after prolonged use. Some films made from recycled materials turn yellow rapidly under prolonged sunlight exposure, which seriously undermines the screen display effect.

Third, there are no unified specifications for production techniques and product safety. Low-end films adopt inferior AB adhesive, which may release harmful substances at high temperatures. Residual glue left after removal will corrode the screen coating. Films with poorly processed edge carving are prone to chipping and may cut users' hands. In addition, there are no classification standards for impact resistance. Some seemingly thick films will shatter when dropped from a height of one meter, and broken glass fragments may cause cuts.

Back in early 2024, the Guangdong Electronic Digital Industry Association, together with more than 20 leading enterprises including SmartDevil, Mingyihu, PISEN and Lens Technology, released the association standard T/GDEDIA 0005—2024 to unify testing methods in advance. In August 2025, the Ministry of Industry and Information Technology (MIIT) officially issued the building material industry standard JC/T 2921-2025, which was scheduled for mandatory implementation in March 2026. It now serves as the official basis for national law enforcement and random quality inspections.

II. In-depth Analysis of the Three Mandatory Core Thresholds

1. Mechanical Hardness: Mohs Hardness ≥ 9H, Putting an End to Misleading Hardness Marketing

The new standards take the Mohs mineral hardness test method as the unified evaluation criterion and phase out the previously disordered self-certification mode based on pencil hardness. A qualified tempered glass film shall have a minimum surface Mohs hardness of 9H. The testing procedure is standardized: a standard graded Mohs hardness test pen is used to scratch the film surface at a constant speed at five different positions, and the product is qualified only if no tiny scratches can be seen by the naked eye. In terms of raw materials, ordinary soda-lime glass has a maximum Mohs hardness of merely 5.5 to 6, which fails to meet the minimum requirement of the new standards. Mid-range mainstream high-alumina-silica glass can steadily reach a Mohs hardness of 7 to 8 after intensive chemical tempering. To consistently hit the 9H threshold, manufacturers have to adopt lithium-aluminum-silica nano-crystalline glass substrates, which directly promotes the upgrading of upstream raw materials. Data from industrial testing institutions indicates that in market random inspections conducted in the first quarter of 2026, only 31% of low-cost unbranded films passed the hardness test, while leading brands such as SmartDevil, Benks and Mingyihu achieved a 100% qualification rate across all product lines. High-end nano-crystalline films generally have a Mohs hardness ranging from 9.2 to 9.5, with their resistance to abrasion from sand and gravel increased several times.

2. Optical Transmittance ≥ 90%: Safeguard the Original Color Performance of Screens

A full-spectrum visible light transmittance of no less than 90% is set as a strict threshold for high-definition tempered glass films. Separate graded criteria are formulated for special functional films such as privacy protection films and frosted films. For anti-reflection (AR) optical films, the recommended transmittance is above 95%.All tests follow the spectrophotometric method specified in standard GB/T 2410, covering the entire visible light spectrum from 400nm to 700nm, so as to prevent test fraud by only detecting a single wavelength band.Insufficient transmittance will bring obvious drawbacks. Every 5% drop in transmittance will degrade the perceived brightness of the screen. OLED screens are more prone to rainbow patterns and color deviation. By contrast, qualified films with a transmittance above 90% can deliver color reproduction nearly identical to that of a bare screen.In 2026, mainstream high-end AR sputtering films generally achieve a transmittance of 93% to 96%, and have become standard accessories for flagship smartphones.

2. Haze ≤ 1.5%: Eliminate Hazy and Blurred Visual Defects

Haze refers to the degree of light scattering. A higher haze value leads to a duller screen and lower definition. The new standards mandate a maximum haze value of 1.5% for all high-definition tempered glass films. Inferior recycled glass, rough polishing and uneven coating application will push the haze up to 2.5% or even 4%. By contrast, qualified substrates made of high-alumina-silica glass and nano-crystalline glass, combined with precision edge carving and vacuum coating technologies, can easily keep the haze within the range of 0.8% to 1.2%. For foldable screens and vehicle-mounted curved large screens, supplementary requirements on haze uniformity for curved surfaces are added, stipulating that the haze fluctuation at curved areas shall not exceed 0.3%, which addresses the long-standing problems of blurry edges and disjointed visual and tactile experience of curved screen films.

The implementation of these mandatory standards in 2026 marks a pivotal turning point for the tempered glass film industry, shifting its focus from cut-throat price competition centered on cost control to value competition based on technology and product quality. Over the next three years, the three core thresholds including Mohs hardness of 9H, light transmittance of 90% and haze of 1.5% will serve as the fundamental entry requirements for the industry. On this basis, anti-reflection optical films, ultra-thin 0.1mm nano-crystalline films, composite films for foldable screens and automotive-grade protective films will foster new growth momentum. As domestically produced glass substrates, coating equipment and testing systems continue to mature, China's tempered glass film industry is expected to cast off the label of low-end OEM manufacturing and build a complete high-end industrial chain with global competitiveness. This will not only safeguard consumers' safety and visual experience, but also drive the high-quality and standardized development of the entire consumer electronics accessories sector.