Glass Composition for Several Commercial Borosilicates between 1900 and 2016. (A) Pyrex 33-expansion Borosilicate, (B) Schott Jena Fiolax Glass, and (C) Kimble's 51-expansion Borosilicate
| A | ||||
|---|---|---|---|---|
| Weight% | Pyrex 191833 | Pyrex 194734 | Pyrex 198535 | Pyrex 201136 |
| SiO2 | 80.5 | 80.6 | 80.5 | 81.5 |
| Al2O3 | 2.0 | 2.2 | 2.2 | 2.3 |
| B2O3 | 11.8 | 12.8 | 12.9 | 12.3 |
| Na2O | 4.4 | 3.5 | 3.8 | 3.9 |
| K2O | 0.2 | 0.4 | 0.4 | |
| B | ||||
|---|---|---|---|---|
| Weight% | Jena 191833 | Jena 193724 | Fiolax 201136 | Fiolax 201637 |
| SiO2 | 65 | 65 | 74.6 | 75 |
| Al2O3 | 4.2 | 4 | 5.6 | 5.4 |
| B2O3 | 10.7 | 11 | 10.9 | 10.5 |
| Na2O | 7.8 | 7.5 | 6.9 | 7.1 |
| CaO | 0.6 | 1.5 | 1.5 | |
| ZnO | 10.9 | 11 | ||
| As2O3 | 0.2 | 0.1 | ||
| C | ||||
|---|---|---|---|---|
| Weight% | Kimble N.C. 193024 | Kimble N-51-A 195838 | Kimble N51A 196839 | Gerresheimer N51A 201436 |
| SiO2 | 73.8 | 74.0 | 74.6 | 72.7 |
| Al2O3 | 5.5 | 5.4 | 5.5 | 6.6 |
| B2O3 | 9.6 | 9.1 | 9.4 | 11.3 |
| Na2O | 6.5 | 6.4 | 6.2 | 6.0 |
| K2O | 0.9 | 0.6 | 2.6 | |
| MgO | 0.5 | 0.2 | 0.3 | |
| CaO | 0.6 | 0.9 | 0.9 | 0.5 |
| BaO | 3 | 2.9 | 2.2 | |
| ZnO | 0.6 | |||
| As2O3 | 0.1 | |||