ULE 7972
also Corning 7972
ULE 7972 (Corning 7972) is a titania-doped fused silica with a near-zero coefficient of thermal expansion, supplied in standard, premium and mirror CTE classes.
Reference datasheet — ULE 7972 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
ULE 7972 tempers and conditions
ULE 7972 is supplied in one standard condition, PREM.
Supply forms, finishes and certifications
Ways ULE 7972 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
MIRROR | Mirror Substrate / Structural Grade | Surface finish |
STDDefault | Standard Grade | Standard supply |
What is ULE 7972?
ULE 7972 (Corning 7972) is a titania-doped fused silica with a near-zero coefficient of thermal expansion, supplied in standard, premium and mirror CTE classes. Engineers select it as a dimensionally stable substrate for precision optics — telescope and EUV mirror blanks, metrology artefacts — with service to 890 °C, in boule, sliced blank and lightweighted forms. Machinability is low (score 15): only diamond and abrasive processes apply, deep lightweighting is slow, and blank cost and lead time are high. Zerodur is the nearest alternative where a glass-ceramic substrate is acceptable. ULE 7972 has a density of 2.21 g/cm³ (0.0798 lb/in³), lighter than 88% of glass grades. ULE 7972 has a tensile strength of 50 MPa (7.25 ksi), stronger than 59% of glass grades. The elastic modulus is 67.6 GPa (9.8 Msi).
What is ULE 7972 used for?
- Telescope mirror blanks
- EUV lithography optics
- Metrology standards
Advantages
- Lightweight — 2.21 g/cm³ (0.0798 lb/in³), better than 88% of glass grades
- High service temperature — 890°C (1,634 °F), better than 83% of glass grades
- Good corrosion resistance — 92/100, better than 81% of glass grades
ULE 7972 properties
Typical room-temperature values; bars are the position among glass grades.
Physical4
ULE 7972 has a density of 2.21 g/cm³ (0.0798 lb/in³), lighter than 88% of glass grades.
Mechanical11
ULE 7972 has a tensile strength of 50 MPa (7.25 ksi), stronger than 59% of glass grades. The elastic modulus is 67.6 GPa (9.8 Msi).
Thermal5
ULE 7972 is rated for continuous service to 890°C (1,634 °F). It conducts heat at 1.3 W/m·K (0.757 BTU/hr·ft·°F), worse than 51% of glass grades. Thermal expansion is 0 µm/m·K (0 µin/in·°F).
Electrical5
ULE 7972 is an electrical insulator with a dielectric strength of 25 kV/mm (635 V/mil) and a resistivity of 1×10¹⁶ Ω·m.
Chemical & Environmental2
Corrosion resistance is excellent (92/100), better than 81% of glass grades.
Sustainability4
Producing a kilogram of ULE 7972 takes about 200 MJ of energy and emits 14 kg of CO₂ — more than 71% of glass grades. Typical recycled content is 0%.
Manufacturability2
ULE 7972's machinability is poor (15/100, worse than 54% of glass grades).
Common Calculations3
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the glass family
Yield strength against density for every glass grade FabDigit runs. ULE 7972 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with ULE 7972
Is ULE 7972 easy to machine?
Diamond grinding, core drilling and ultrasonic/abrasive-waterjet machining only; deep pocket lightweighting to >80 % mass removal is routine but slow and chip-out prone at edges.
Can ULE 7972 be welded?
Joined by low-temperature frit bonding, hydroxide-catalysis bonding or high-temperature fusion sealing of ULE-to-ULE; never metal-welded, and thermal joining requires careful re-annealing to preserve CTE uniformity.
Can ULE 7972 be formed, bent or molded?
Supplied as flame-hydrolysis boules that are sliced and slumped/fused near 1500 °C; slumping and any hot work must be followed by controlled annealing around 1000 °C.
ULE 7972 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 |
|---|---|---|
| TiO2titania dopant sets the zero-crossing temperature of CTE | 6.5 – 9 | 7.5 |
| OHresidual hydroxyl from the flame process | 0 – 0.12 | 0.08 |
| SiO2synthetic silica from flame hydrolysis | ≥ 91 (balance) |
What surface finishes work on ULE 7972?
Polishes to sub-nanometre rms with cerium oxide and ion-beam figuring; optical coatings (Mo/Si multilayer, Al+MgF₂) adhere well, and acid etching with HF is used only for subsurface-damage removal.
Equivalent designations
Standards and trade names that resolve to ULE 7972 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Trade names
- Corning 7972
How much does ULE 7972 cost?
ULE 7972 is a high-cost glass ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
ULE 7972 — frequently asked
What is ULE 7972 used for?
ULE 7972 is typically used for telescope mirror blanks, EUV lithography optics and metrology standards. In short: near-zero CTE substrate; lightweightable mirror blank; zerodur-class stability.
What is the tensile strength of ULE 7972?
ULE 7972 has a typical tensile strength of 50 MPa (7.25 ksi) — stronger than 59% of glass grades.
Is ULE 7972 easy to machine?
Not especially — machinability is rated poor (15/100, worse than 54% of glass grades). Diamond grinding, core drilling and ultrasonic/abrasive-waterjet machining only; deep pocket lightweighting to >80 % mass removal is routine but slow and chip-out prone at edges.
Can ULE 7972 be welded?
Joined by low-temperature frit bonding, hydroxide-catalysis bonding or high-temperature fusion sealing of ULE-to-ULE; never metal-welded, and thermal joining requires careful re-annealing to preserve CTE uniformity.
What surface finishes work on ULE 7972?
Polishes to sub-nanometre rms with cerium oxide and ion-beam figuring; optical coatings (Mo/Si multilayer, Al+MgF₂) adhere well, and acid etching with HF is used only for subsurface-damage removal.
Can ULE 7972 be formed, bent or molded?
Supplied as flame-hydrolysis boules that are sliced and slumped/fused near 1500 °C; slumping and any hot work must be followed by controlled annealing around 1000 °C.
What is the maximum service temperature of ULE 7972?
ULE 7972 is rated for continuous use to about 890°C (1,634 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does ULE 7972 cost?
ULE 7972 is a high-cost glass ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- ULE Corning Code 7972 Ultra Low Expansion Glass — Product Information — Corning Incorporated (Specialty Materials) (2016)
- Engineered Materials Handbook Vol. 4: Ceramics and Glasses — ASM International (1991)
- Properties of low-expansion optical substrate materials (ULE vs Zerodur vs fused silica) — SPIE Proceedings compilations (2014)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.