Tempered

Purpose. Tempered (strengthened) safety glass for doors, shop windows, partitions, balustrades, canopies, structural facade glazing, furniture and ground transport.

Construction and properties. Bending strength — 120 MPa (float glass) / 90 MPa (patterned glass), 4–5 times higher than annealed glass. On breakage it shatters into small, safe fragments (at least 40 fragments per reference area for thicknesses of 4–12 mm). Enhanced thermal-shock resistance (withstands a temperature differential of roughly 150–200 °C). Soft-body impact-resistance classes — CM1…CM4. Typical thicknesses — 4, 5, 6, 8, 10, 12, 15, 19 mm.

Governing standards. GOST 30698-2014 "Tempered glass. Technical specifications" (complies with Russian national standard, mandatory for the Russian market).

Points to note. After tempering, glass CANNOT be cut, drilled or edge-processed — all such operations must be completed before tempering. Sandblasted glass cannot be tempered afterward. For critical projects, order a heat-soak test (to guard against spontaneous breakage caused by nickel sulphide (NiS) inclusions) — this is a separate specification requirement, not covered by the base GOST.

Update to GOST 30698-2014 (Amendment No.1, effective 01.11.2025). The scope of application has been extended, methods for checking appearance and protection class clarified, and a requirement introduced for rounded edges with radius R≥4 mm (protection against thermal shock and micro-cracking). All UNIALGLASS products are edge-processed with a radius of R≥4 mm.