Tempered glass is significantly stronger than ordinary (annealed) glass, typically about 4 to 5 times stronger in terms of both surface strength and resistance to bending, but it remains much more brittle and will shatter into small, blunt pieces when broken. Key points about tempered glass strength:

• Surface and edge compression: Tempered glass is treated so its outer surfaces are in a state of compressive stress, which increases the load the glass can bear before cracking. This gives it several times higher surface strength than annealed glass. The compressive surface stresses are a primary reason for its enhanced performance under impact and bending [web results from safety and materials sources].
• Overall mechanical strength: Under bending and impact, tempered glass can withstand higher forces before initiating a crack, often cited as roughly 4 to 5 times the strength of normal glass of the same thickness [web results].
• Thermal resistance: Tempered glass also handles rapid temperature changes better than ordinary glass, contributing to its suitability in environments with heat exposure (ovens, stove doors, fireplace screens) [web results].
• Failure mode: When tempered glass does fail, it tends to break into many small, blunt fragments rather than sharp shards, which reduces the severity of injury but means the entire pane typically needs replacement [web results].
• Limitations: Tempered glass cannot be easily cut or drilled after tempered; edges must be prepared before tempering, and any holes or notches can become stress risers. If damaged, it usually fails suddenly rather than showing gradual yield [general industry knowledge].

Practical implications:

• For safety-critical or high-impact applications (shower doors, car windows, storefronts), tempered glass offers a strong safety advantage over regular glass.
• For scenarios requiring cutting, drilling, or large, uninterrupted panes with minimal edges, annealed or laminated alternatives may be used, since tempered glass cannot be modified after tempering.

If you’d like, I can tailor this to a specific thickness or用途 (e.g., shower doors vs. automotive glazing) and provide approximate stress ranges for those cases.