John Moncrieff Ltd has been producing toughened sight glasses for over 100 years, we are often asked, what is toughened glass and what are its benefits
The term Glass Toughening is interchangeable with tempering, it is one method used to create a safety glass. Tough flat glass will create a product that has 4 times the strength of standard annealed glass, and if it breaks it will break into small square pieces, rather than sharp shards, making injury or damage to equipment less likely.
| Annealed Glass | Toughened Glass |
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Method
The most common method is with the use of heat. The glass part is formed as normal, then it is reheated to almost melting point, the surface of the glass is blasted with cold air. This has the effect of cooling the outside of the glass, whilst the inner core remains hot. This creates a compressive stress within the glass. This compressive stress is in effect and creates a strength of 4 times that of standard annealed glass.
You can see the compressive strength if you look at the glass under a polarised light
| Annealed Glass | Toughened Glass |
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Products
John Moncrieff Ltd produces all our standard sight and gauge glass products using either borosilicate or soda lime glass, making it as safe as possible for use
In many cases our sight and gauge glass products are used in hazardous areas, on Oil Rigs, Chemical plants etc where safety is paramount
| Gauge Glass | Circular Sight Glass |
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Benefits
Safety – 4 time stronger that standard annealed glass, additionally when it breaks, it breaks into little square pieces, as you would see in a shattered car windscreen. not in sharp shards..
Durability – 4 times stronger increases the durability and life span of the item.
Economic – longer lasting products means, less machinery down time on maintenance
Application
Toughened Glass has many applications, for John Moncrieff Ltd we use toughened glass as our standard method for producing
Reflex and Transparent Gauge Glasses (Maxos Data Sheet)
Circular Sight Glasses/ Pet Glasses.
Flat panels and other flat shapes
Recently we are also now offering toughened glass tubing
If you would like more detailed information on toughened glass products, please contact us
