Tempered glass and semi tempered glass (also known as heat strengthened glass) both require heat treatment, but their strength and purpose are different.
Tempered glass:
·Cooling process: fast, with high surface stress (10000 psi)
·Strength: The strength is four to five times that of ordinary float glass
·Safety: Safety glass. Broken into small and dull fragments
·Usage: Doors, shower rooms, windows, furniture
Semi tempered glass (also known as heat strengthened glass):
·Cooling process: Slow, with lower surface stress (3500-7500 psi)
·Strength: The strength is twice that of ordinary float glass
·Safety: Non safety glass. When broken, larger fragments and radioactive cracks will form
·Purpose: Application fields that require high imaging requirements and certain tempered glass properties

