Difference Between Glass and Pyrex (With Table)

Glasses were invented nearly in the 17th century and is used to date and have been majorly improved upon. Glasses are made from soda-lime, sand, silicon dioxide, limestone, calcium carbonate, and sodium carbonate, which then undergo temperature and pressure changes to finally form the glass we use. The use of glasses varies from windows, doors, utensils, monitors, and so on. There are four types of glasses like annealed glasses, heat-strengthened glasses, tempered glasses, and laminated glasses. Pyrex glasses are a brand name and it basically tempered glass and have more strength. 

Glass vs Pyrex

The difference between glass and pyrex is that pyrex is more strong, fire-proof, which means that it can withstand greater temperature fluctuations and shatterproof as well when compared to normal glasses which cannot handle such temperature fluctuations.   

Comparison Between Glass and Pyrex

Parameters of comparisonGlassPyrex
What it meansNormal everyday glass.It is a sub-type of glasses that is heat resistant. It is essentially a brand name.
UsedFor window panes, glasses, packing, housing, and so on.Laboratory materials like test tubes, dishes, beakers, and kitchen utensils like cookware baking ware. 
StrengthNot shatterproofIt is shatterproof.
Fire resistanceNot fire-resistant.It is fire-resistant. 

What is Glass?

Technically speaking glass is liquid sand, even though it is not exactly solid or liquid. Sand melts at a very high temperature, and when it reaches the melting point it undergoes a complete transfusion. There are other types of glasses that are made up of different materials like silicon dioxide, calcium carbonate, etc all subjected to very high temperature and pressure. The chemistry of glasses is also very interesting as it is neither liquid nor solid, it is an amorphous solid which is like a supercooled liquid. 

There are four types of glasses like annealed glasses which is molten glass that is allowed to cool down in a controlled manner till it reaches the temperature of the room. The next is Heat Strengthened glass which is semi tempered or toughened which involves annealing up to 700 or 650 degrees, this causes the glass to increase the mechanical and thermal strength twice as the previous one. The third is tempered and toughened glasses where the cooling rate is different which causes the glass to have different physical properties and the surface strength is increased significantly. The fourth type is laminated glass which reduces the safety hazard with shattered glass fragments. 

The uses of glasses are in kitchens, windows panes, glasses, dishes, micro ovens are so on. In greenhouses, the glasses are important to maintain the temperatures within the greenhouse. 

What is Pyrex?

Pyrex is essentially a brand name which is a tempered glass that is made up of different elements from borosilicate to soda-lime and so on. Initially, it was made of borosilicate which was composed of 4% boron, 54% oxygen, 2,8% sodium, 1.2% aluminum, 37,7% silicon, and potassium. But later the manufacturer changed the formulation to use soda-lime instead of borosilicate in order to increase the mechanical strength of the material to make it almost shatterproof. However, the borosilicate had more thermal resistance making it better for laboratory and even cooking work. 

As Pyrex is shatterproof, heat resistant, and even erosion-resistant, pyrex has found wide usage in labs where beakers, dishes, test tubes, pitot tubes and even measuring cylinders are made up of borosilicates or soda-lime. In kitchen utensils especially the ones which are used for baking, microwaving as they are required to withstand higher temperatures. 

Pyrex is six to eight times stronger than glass and thus also more costly as they are more difficult to make. There are two main processes involved in this which are batching and forming, in the former process where one large batch of pyrex is formed, and before the manufacturing begins the raw materials are pulverized and granulated in uniform-sized particles and stored in towers. The second method that is forming liquid glass is made to flow and collected quickly and tempered to get the final product. 

Glass blowing is a rather famous technique that is used to make glassware and other similar stuff, and after the maker gets the desired shape they close the mold, cool it, and then color or polish it to make it better for the market value. Quality control is really important as there have been cases of an explosion of pyrex bowls in the microwave so it is important to get the composition right along with the temperature and pressure applied to form the products.  

Main Difference Between Glass and Pyrex

  1. Pyrex is a brand name, it is made up of glass itself but tempered glass and previously it was made of borosilicate. Glass is made from natural materials like sand, limestone, and soda ash which is made into the glass under high temperature and pressure.
  2. The Pyrex is shatterproof nearly while the glass is mostly flimsy. 
  3. The pyrex is fire resistant while the glass is not
  4. Pyrex is used in laboratories like test tubes, Petri dishes and beakers, kitchen utensils, and other industries where there are temperature fluctuations while glasses are used for less taxing tasks.
  5. Pyrex is six to eight times harder than a simple glass as it has a granular breaking pattern.   


Thus the major difference between pyrex and glass is that pyrex is essentially a brand name given to tempered glass which is nearly shatterproof, corrosion-proof, and even heat resistant and can be best suited for usage in laboratories and kitchens for baking. Glass on the other hand is finer and better for other lighter tasks and it is also more affordable and easy to manufacture as well. 


  1. https://aip.scitation.org/doi/abs/10.1063/1.2805043
  2. https://iopscience.iop.org/article/10.1088/0960-1317/5/2/010/meta