Pyrex 7740 TEMP
Grade
ASTM E438 Type I · also Corning 7740
TEMP = thermally toughened (tempered) borosilicate
Pick for pressure sight glasses, oven doors, cooktop and safety panels where 3–5× bending strength and higher thermal shock capability are needed; cannot be cut or drilled after tempering.
Values for the TEMP condition
Other Pyrex 7740 tempers and conditions
Pyrex 7740 is listed in 3 conditions; see the grade overview at Pyrex 7740.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ANNDefault Annealed | Default state for laboratory glassware, tubing, sight glasses and optics; can be cut, drilled and flame-worked. | — | 35 | 0 | 480 HV | 1 W/m·K |
TEMPThis page Thermally toughened (tempered) borosilicate | Pick for pressure sight glasses, oven doors, cooktop and safety panels where 3–5× bending strength and higher thermal shock capability are needed; cannot be cut or drilled after tempering. | — | 60 | 0 | 480 HV | 1 W/m·K |
Chemically strengthened (ion-exchanged) borosilicate | Choose for thin (<3 mm) panes, windows and cover glass where optical flatness must be kept while raising surface strength; strength gain is smaller than in soda-lime glass because of the low alkali content. | — | 70 | 0 | 520 HV | 1 W/m·K |
What is Pyrex 7740 TEMP?
Pyrex 7740 TEMP is Pyrex 7740 in the TEMP grade — pick for pressure sight glasses, oven doors, cooktop and safety panels where 3–5× bending strength and higher thermal shock capability are needed; cannot be cut or drilled after tempering. Pyrex 7740 TEMP has a tensile strength of 60 MPa (8.7 ksi), stronger than 74% of glass grades. Elongation at break is 0% and the elastic modulus is 64 GPa (9.28 Msi). Pyrex 7740 TEMP has a density of 2.23 g/cm³ (0.0806 lb/in³), lighter than 85% of glass grades. ANN is the default condition FabDigit quotes; TEMP is available on request or by drawing note.
Advantages
- Low embodied carbon — 1.7 kg CO₂/kg, better than 88% of glass grades
- Lightweight — 2.23 g/cm³ (0.0806 lb/in³), better than 85% of glass grades
- Good corrosion resistance — 92/100, better than 81% of glass grades
Limitations
- Difficult to machine — 3/100, worse than 97% of glass grades
- Limited service temperature — 260°C (500 °F), worse than 83% of glass grades
Pyrex 7740 TEMP properties
Typical room-temperature values for Pyrex 7740 TEMP; 13 are specific to this condition. Other listed values are Pyrex 7740 reference data and may not represent this condition. Bars are the position among glass grades.
Physical4
Pyrex 7740 TEMP has a density of 2.23 g/cm³ (0.0806 lb/in³), lighter than 85% of glass grades.
Mechanical12
Pyrex 7740 TEMP has a tensile strength of 60 MPa (8.7 ksi), stronger than 74% of glass grades. Elongation at break is 0% and the elastic modulus is 64 GPa (9.28 Msi).
Thermal5
Pyrex 7740 TEMP is rated for continuous service to 260°C (500 °F). It conducts heat at 1.1 W/m·K (0.659 BTU/hr·ft·°F), worse than 63% of glass grades. Thermal expansion is 3.3 µm/m·K (1.83 µin/in·°F).
Electrical5
Pyrex 7740 TEMP is an electrical insulator with a dielectric strength of 20 kV/mm (508 V/mil) and a resistivity of 1×10¹³ Ω·m.
Chemical & Environmental2
Corrosion resistance is excellent (92/100), better than 81% of glass grades.
Sustainability4
Producing a kilogram of Pyrex 7740 TEMP takes about 25 MJ of energy and emits 1.7 kg of CO₂ — less than 88% of glass grades. Typical recycled content is 10%.
Manufacturability2
Pyrex 7740 TEMP's machinability is not recommended (3/100, worse than 97% of glass grades).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Pyrex 7740 TEMP
Is Pyrex 7740 easy to machine?
Diamond core drilling, grinding, waterjet or CO₂/ultrafast laser only; always machine before tempering and re-anneal after heavy grinding.
Can Pyrex 7740 be welded?
Joined by flame or lathe glass-working at 800–1250 °C; seals matched to Kovar and to other 3.3 borosilicates, but not directly to soda-lime glass.
Can Pyrex 7740 be formed, bent or molded?
Formed by float, tube-drawing, pressing or blowing near the working point (~1250 °C); annealing point 560 °C, strain point 510 °C.
What surface finishes work on Pyrex 7740?
Fire polishing, optical polishing, acid etching (HF frosting), chemical strengthening or AR/ITO coating; edge seaming markedly raises usable strength.
Pyrex 7740 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| B2O3≥8 % required for borosilicate 3.3 per ISO 3585 | 12 – 13.5 | 13 |
| Na2O | 3.5 – 4.5 | 4 |
| Al2O3 | 2 – 2.5 | 2.3 |
| K2Otrace, melt dependent | 0 – 0.6 | 0.1 |
| SiO2network former | ≥ 80 (balance) | — |
Pyrex 7740 TEMP — frequently asked
What is Pyrex 7740 TEMP used for?
Pyrex 7740 TEMP is typically used for laboratory glassware, bakeware, sight glasses and chemical piping. In short: benchmark borosilicate 3.3; low-cost thermal-shock glass; kovar-matched sealing glass.
What is the tensile strength of Pyrex 7740 TEMP?
Pyrex 7740 TEMP has a typical tensile strength of 60 MPa (8.7 ksi) — stronger than 74% of glass grades. Strength varies by condition: see the 3 listed tempers.
Is Pyrex 7740 TEMP easy to machine?
Not especially — machinability is rated not recommended (3/100, worse than 97% of glass grades). Diamond core drilling, grinding, waterjet or CO₂/ultrafast laser only; always machine before tempering and re-anneal after heavy grinding.
Can Pyrex 7740 TEMP be welded?
Joined by flame or lathe glass-working at 800–1250 °C; seals matched to Kovar and to other 3.3 borosilicates, but not directly to soda-lime glass.
What surface finishes work on Pyrex 7740 TEMP?
Fire polishing, optical polishing, acid etching (HF frosting), chemical strengthening or AR/ITO coating; edge seaming markedly raises usable strength.
Can Pyrex 7740 TEMP be formed, bent or molded?
Formed by float, tube-drawing, pressing or blowing near the working point (~1250 °C); annealing point 560 °C, strain point 510 °C.
What is the maximum service temperature of Pyrex 7740 TEMP?
Pyrex 7740 TEMP is rated for continuous use to about 260°C (500 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- ASTM E438 — Standard Specification for Glasses in Laboratory Apparatus (Type I Class A) — ASTM International (2021)
- ISO 3585 — Borosilicate glass 3.3, properties — ISO (1998)
- Corning Code 7740 Pyrex glass properties sheet — Corning Incorporated (2014)
- BOROFLOAT 33 technical datasheet (mechanical, thermal, electrical, optical) — SCHOTT AG (2023)
- Engineered Materials Handbook Vol. 4: Ceramics and Glasses — ASM International (1991)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.