JEB Temperfect™ Heat-Treated Glass

J.E. Berkowitz has three state-of-the-art horizontal tempering ovens that produce the highest quality of heat strengthened and fully tempered glass. Heat-Treated glass is:

• Governed by ASTM C1048-04, ASTM C1279-06 and ASTM C1651-08
• Individually tested by SGCC
• Not warranted against breakage, mechanical or thermal failure
• Intended Uses – Where safety glazing is specified and/or where required for mechanical, thermal, or deflection purposes.

Quality Specification

Roller-wave distortion for 1/4″ glass – JEBs internal target is to maintain a limit of .003 peak to valley, excluding the lead and trail edges (10”) with an allowable .008”. Industry guideline for 1/4″ heat-treated glass suggest a tolerance of not to exceed .006” peak to valley, excluding the lead and trail edges (10”) with an allowable .010”.

Bow and Warp for 1/4″ glass can be targeted not to exceed 1/32″ per lineal foot.

1. Directional Heat Treating is recommended and should be parallel to the width dimension (maximum 84”).
2. Optics – Peak to Valley Roller Mark Distortion Heat-treated glass, assembled into either IG units or laminated glass, or both, and installed in a sloped or vertical application, may exhibit increased levels of distortion. This is INHERENT in the HT process, with other factors, including temperature, atmosphere, barometric changes and the glazing systems impact on the glass surface.
3. No ASTM standard currently exists for tolerances, but an ASTM methodology for measurement, in-plant on monolithic heat-treated glass, using either an approved flat bottom or 3-point gauge exists.

JEB recommends the use of full size mockups for visual and approval purposes.

Heat-Strengthened Glass

Heat-strengthened glass is flat glass that has been heat treated to have a surface compression between 3,500 and 7,500 psi (24 to 52 MPa) which is twice the surface compression of annealed glass and meets the requirements of ASTM C 1048. It is intended for general glazing, where additional strength is desired to withstand wind loads and thermal stresses. However, heat-strengthened glass is not a safety glazing material.

Heat-Strengthened Applications:

• Windows
• Insulating Glass Units (IGUs)
• Laminated Glass

Fully Tempered Glass

Fully tempered class is flat glass that has been heat-treated to have a minimum surface compression of 10,000 psi (69MPa) resulting in resistance to impact of approximately four times that of annealed glass. Fully tempered glass will meet the requirements of ANSI Z97.1 and CPSC 16 CFR 1201 and is considered a safety glazing material.

Application Use:

• Storefronts
• Point Supported Glass Wall Systems
• Windows
• Insulating Glass Units (IGUs)
• All Glass Doors
• Entrances
• Railings
• Commercial Shower Doors

Fully Tempered Glass
Minimum Tempering Size – 4 1/2″ x 14″
Maximum Tempering Size – 96″ x 180″

Recommended Maximum Sizing

Fully Tempered Glass (Based on glass thickness)

*Consult JEB for applicable maximum glass sizes