VCCA Home Forums TECHNICAL - GENERAL Upholstery - Interiors & Glass tempered glass

I recently discovered that the rear window and the two rear quarter windows of my '39 business coupe were made of tempered safety glass (not laminated safety glass). The windshield, two door glasses, and the vent window glasses are laminated safety glass just as any other car of this era that I have seen. I suspect that the rear window and quarter windows are original but all of the other glass has been changed sometime in the past. My question is: Does anyone know when Chevrolet started using tempered safety glass and discontinued using laminated safety glass. The glass shop owner is an old car guy and he says he has never seen tempered glass in a car this old.

The website https://auto.howstuffworks.com/car-driving-safety/safety-regulatory-devices/auto-glass1.htm has this iinformation:

"In addition to laminated glass, automakers began to use tempered glass in the late 1930s. This type of glass is used in the vehicle's side and back windows and gains its strength through a heating and rapid cooling process that strengthens the glass' outer surface as well as its core."

So it is possible that the tempered glass is original. Will take more searching to determine if GM or most particularly Chevrolet used tempered glass in 1939 Business Coupe.

On a GM cars the original laminated glass had the LOF logo in one corner and it was also dated, Tempered glass did not have the LOF logo.
Any curved glass was tempered. Some 1937-1939 bodies has tempered glass in stationary windows.
In the parts book GM described tempered as SOLID safety plate.