ASTM C1422_C1422M-20A - Standard Specification for Chemically Strengthened Flat Glass

1.1 This specification covers the requirements for chemically strengthened glass products that are used in general building construction, transportation, solar, and other electronic applications, such as PC screens, notebooks, tablets, smart phones, and E-readers, as well as copy machine scanners, computer disks, and flat glass screens for television monitors. The technique covered in this specification usually involves conducting ion exchange of constituent alkali ions in a glass product by immersing it in a bath of molten salt containing larger alkali ions. Penetration of the larger ions into smaller host sites produces a layer of compression on the surface which strengthens the glass. Techniques such as ion implantation, dealkalization, etch-strengthening, and glaze coatings are specifically excluded from this specification.

1.2 Classification of chemically strengthened glass products is based on the laboratory measurements of surface compression and case depth (depth of compression) and not on the modulus of rupture (MOR). This specification does not purport to address end-use performance.

1.3 A test method for the measurement of case depth and surface compression is included in Section 8. Another test method for similar measurement using optically guided-wave equipment is included in Section 9.

1.4 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.

1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.