Horticultural Glass always like 3mm or 4mm clear float glass or tempered
The standard size is 610mm*610mm ,457mm*610mm and 1422mm*730mm etc
Any size can be customized .
Greenhouse glass also named horticulture glass, which usually use clear or low iron toughened glass. A toughened glass greenhouse is the perfect choice for greenhouse gardeners that live in temperate climates like the UK, Holland, Italy, Belgium..where the greenhouse may be exposed to high winds.
High light transmittance give the plant more light and vigorous growth.
The extra weight in toughened glass gives your greenhouse much greater resistance to high winds and will stop your greenhouse frame from moving and twisting as the heavy glass keeps each section "square" under wind loads. ripening!
Toughened greenhouse glass is made by passing normal cut glass through a high temperature furnace that heats up the outside of the glass very quickly, creating tension on it's surface that hardens the glass. This glass will take an impact from the kid's football without a problem, but not a golf or cricket ball.
A greenhouse with safety glass is safer for your family and will have a longer life than a greenhouse without it.