ZERODUR · heat-treated state · default condition
ZERODUR Annealed Glass
Properties of the Annealed Glass condition, compared with the other ZERODUR tempers.
Default commercial delivery state: ceramized, fine-annealed blank with CTE 0 ± 0.10 ×10⁻⁶/K — use for general precision optics and mechanical metrology parts.
What is ZERODUR Annealed Glass?
ZERODUR Annealed Glass is ZERODUR heat treated to Annealed Glass — default commercial delivery state: ceramized, fine-annealed blank with CTE 0 ± 0.10 ×10⁻⁶/K — use for general precision optics and mechanical metrology parts. ZERODUR Annealed Glass has a tensile strength of 30 MPa (4.35 ksi), weaker than 86% of glass grades. The elastic modulus is 90.3 GPa (13.1 Msi). ZERODUR Annealed Glass has a density of 2.53 g/cm³ (0.0914 lb/in³), lighter than 65% of glass grades.
Advantages
- Tough — resists crack growth — 0.9 MPa·√m (0.819 ksi·√in), better than 75% of glass grades
ZERODUR Annealed Glass properties
Typical room-temperature values for ZERODUR Annealed Glass — 6 properties are specific to this condition; the rest are grade-level values shared by every ZERODUR temper. Each bar shows where the value sits among the glass grades in FabDigit's library — further right is higher.
Physical4
ZERODUR Annealed Glass has a density of 2.53 g/cm³ (0.0914 lb/in³), lighter than 65% of glass grades.
Mechanical11
ZERODUR Annealed Glass has a tensile strength of 30 MPa (4.35 ksi), weaker than 86% of glass grades. The elastic modulus is 90.3 GPa (13.1 Msi).
Thermal5
ZERODUR Annealed Glass is rated for continuous service to 500°C (932 °F). It conducts heat at 1.5 W/m·K (0.844 BTU/hr·ft·°F), better than 58% of glass grades. Thermal expansion is 0 µm/m·K (0 µin/in·°F).
Electrical5
ZERODUR Annealed Glass is an electrical insulator with a dielectric strength of 20 kV/mm (508 V/mil) and a resistivity of 1×10¹² Ω·m.
Chemical & Environmental2
Corrosion resistance is excellent (85/100), better than 62% of glass grades.
Sustainability4
Producing a kilogram of ZERODUR Annealed Glass takes about 90 MJ of energy and emits 6.5 kg of CO₂ — more than 63% of glass grades. Typical recycled content is 0%.
Manufacturability3
ZERODUR Annealed Glass's machinability is poor (20/100, better than 57% 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.
Other ZERODUR tempers and conditions
ZERODUR is also supplied in 5 other conditions. The full side-by-side table is on the ZERODUR overview.
- Annealed GlassDefaultDefault commercial delivery state: ceramized, fine-annealed blank with CTE 0 ± 0.10 ×10⁻⁶/K — use for general precision optics and mechanical metrology parts.6 properties
Working with ZERODUR Annealed Glass
Is ZERODUR easy to machine?
Diamond grinding, core drilling, lapping and ultrasonic machining only — no conventional cutting; keep coolant flooded and avoid edge chipping, then acid-etch or fine-grind to remove subsurface damage.
Can ZERODUR be welded?
Not weldable; parts are joined by optical contacting, low-stress epoxy/silicate bonding, frit bonding or Invar/steel flexure mounts.
Can ZERODUR be formed, bent or molded?
Supplied as cast, ceramized blanks; near-net shapes (lightweighted honeycomb mirrors) are produced by machining the blank, not by hot forming, since re-heating above ~600 °C alters the crystal phase and CTE.
What surface finishes work on ZERODUR?
Polishes to sub-nanometre rms and accepts ion-beam figuring plus Al/Ag/dielectric and multilayer coatings; a light etch after grinding recovers much of the bending strength.
ZERODUR 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 |
|---|---|---|
| SiO2network former | 54 – 58 | 55.5 |
| Al2O3 | 24 – 26 | 25.3 |
| P2O5 | 6.5 – 8.5 | 7.5 |
| Li2Oforms high-quartz solid solution crystals | 3 – 4.5 | 3.7 |
| TiO2nucleating agent | 2 – 2.6 | 2.3 |
| ZrO2nucleating agent | 1.5 – 2.2 | 1.9 |
| ZnO | 1 – 1.8 | 1.4 |
| MgO | 0.5 – 1.5 | 1 |
| Na2O | 0.2 – 0.8 | 0.5 |
| K2O | 0 – 0.8 | 0.5 |
| As2O3fining agent in classic composition; arsenic-free melts also offered | 0 – 0.6 | 0.4 |
ZERODUR Annealed Glass — frequently asked
What is ZERODUR Annealed Glass used for?
ZERODUR Annealed Glass is typically used for telescope mirror blanks, astronomical optics, lightweighted honeycomb mirror substrates, metrology reference plates and straightedges, ring laser gyroscope bodies and lithography stages and mask blanks. In short: zero-expansion glass-ceramic.
What is the tensile strength of ZERODUR Annealed Glass?
ZERODUR Annealed Glass has a typical tensile strength of 30 MPa (4.35 ksi) — weaker than 86% of glass grades. Strength varies by condition: see the 6 listed tempers.
Is ZERODUR Annealed Glass easy to machine?
Not especially — machinability is rated poor (20/100, better than 57% of glass grades). Diamond grinding, core drilling, lapping and ultrasonic machining only — no conventional cutting; keep coolant flooded and avoid edge chipping, then acid-etch or fine-grind to remove subsurface damage.
Can ZERODUR Annealed Glass be welded?
Not weldable; parts are joined by optical contacting, low-stress epoxy/silicate bonding, frit bonding or Invar/steel flexure mounts.
What surface finishes work on ZERODUR Annealed Glass?
Polishes to sub-nanometre rms and accepts ion-beam figuring plus Al/Ag/dielectric and multilayer coatings; a light etch after grinding recovers much of the bending strength.
Can ZERODUR Annealed Glass be formed, bent or molded?
Supplied as cast, ceramized blanks; near-net shapes (lightweighted honeycomb mirrors) are produced by machining the blank, not by hot forming, since re-heating above ~600 °C alters the crystal phase and CTE.
What is the maximum service temperature of ZERODUR Annealed Glass?
ZERODUR Annealed Glass is rated for continuous use to about 500°C (932 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in ZERODUR Annealed Glass?
Yes — ZERODUR Annealed Glass is available for CNC machining and sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ZERODUR — Zero Expansion Glass Ceramic, technical data — SCHOTT AG (2023)
- Strength of ZERODUR (TIE-33 / strength brochure) — SCHOTT AG (2021)
- ASM Engineered Materials Handbook Vol. 4: Ceramics and Glasses — ASM International (1991)
- Glass-ceramic property compilations (LAS system) — MatWeb / Ceramic Industry data (2022)
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.