Lead Glass (IEC G-500) CRYSTAL-30
Grade
ISO IEC 60672-3 G-500
CRYSTAL-30 = lead crystal
Pick for decorative/optical crystal: highest brilliance and refractive index, easily cut and polished, but softer and lower service temperature.
Values for the CRYSTAL-30 condition
Other Lead Glass (IEC G-500) tempers and conditions
Lead Glass (IEC G-500) is listed in 3 conditions; see the grade overview at Lead Glass (IEC G-500).
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
G-500Default Standard lead-alkali glass (~24–30 % PbO), annealed | Default electrical/lamp and sealing lead glass: high resistivity, low loss, CTE ~9 µm/m·K for Dumet/soft-glass seals. | — | 45 | — | 420 HV | 0.9 W/m·K |
Radiation shielding lead glass | Pick for X-ray/γ observation windows and hot-cell glazing where lead equivalence per unit thickness governs. | — | — | — | 330 HV | 0.7 W/m·K |
CRYSTAL-30This page Lead crystal | Pick for decorative/optical crystal: highest brilliance and refractive index, easily cut and polished, but softer and lower service temperature. | — | — | — | 370 HV | — |
What is Lead Glass (IEC G-500) CRYSTAL-30?
Lead Glass (IEC G-500) CRYSTAL-30 is Lead Glass (IEC G-500) in the CRYSTAL-30 grade — pick for decorative/optical crystal: highest brilliance and refractive index, easily cut and polished, but softer and lower service temperature. Lead Glass (IEC G-500) CRYSTAL-30 has a tensile strength of 45 MPa (6.53 ksi), weaker than 56% of glass grades. Elongation at break is 0% and the elastic modulus is 58 GPa (8.41 Msi). Lead Glass (IEC G-500) CRYSTAL-30 has a density of 3.4 g/cm³ (0.123 lb/in³), heavier than 64% of glass grades. G-500 is the default condition FabDigit quotes; CRYSTAL-30 is available on request or by drawing note.
Advantages
- Low embodied carbon — 1.4 kg CO₂/kg, better than 92% of glass grades
Limitations
- Poor heat conductor — 0.9 W/m·K (0.52 BTU/hr·ft·°F), worse than 84% of glass grades
- Limited service temperature — 300°C (572 °F), worse than 80% of glass grades
- Low stiffness — 58 GPa (8.41 Msi), worse than 76% of glass grades
Lead Glass (IEC G-500) CRYSTAL-30 properties
Typical room-temperature values for Lead Glass (IEC G-500) CRYSTAL-30; 11 are specific to this condition. Other listed values are Lead Glass (IEC G-500) reference data and may not represent this condition. Bars are the position among glass grades.
Physical4
Lead Glass (IEC G-500) CRYSTAL-30 has a density of 3.4 g/cm³ (0.123 lb/in³), heavier than 64% of glass grades.
Mechanical12
Lead Glass (IEC G-500) CRYSTAL-30 has a tensile strength of 45 MPa (6.53 ksi), weaker than 56% of glass grades. Elongation at break is 0% and the elastic modulus is 58 GPa (8.41 Msi).
Thermal5
Lead Glass (IEC G-500) CRYSTAL-30 is rated for continuous service to 300°C (572 °F). It conducts heat at 0.9 W/m·K (0.52 BTU/hr·ft·°F), worse than 84% of glass grades. Thermal expansion is 9.5 µm/m·K (5.28 µin/in·°F).
Electrical5
Lead Glass (IEC G-500) CRYSTAL-30 is an electrical insulator with a dielectric strength of 30 kV/mm (762 V/mil) and a resistivity of 1×10¹⁵ Ω·m.
Chemical & Environmental2
Corrosion resistance is good (62/100), worse than 65% of glass grades.
Sustainability4
Producing a kilogram of Lead Glass (IEC G-500) CRYSTAL-30 takes about 18 MJ of energy and emits 1.4 kg of CO₂ — less than 94% of glass grades. Typical recycled content is 20%.
Manufacturability2
Lead Glass (IEC G-500) CRYSTAL-30's machinability is poor (15/100, worse than 54% of glass grades).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Lead Glass (IEC G-500) CRYSTAL-30
Is Lead Glass (IEC G-500) easy to machine?
Grind, core-drill and score with diamond tooling under flood coolant; anneal after heavy grinding and avoid edge chipping — no conventional cutting.
Can Lead Glass (IEC G-500) be welded?
Not weldable; joined by flame/lampworking or by glass-to-metal (Dumet, Ni-Fe) sealing thanks to the ~9 µm/m·K CTE match.
Can Lead Glass (IEC G-500) be formed, bent or molded?
Melts easily at 1300–1400 °C with a long working range; pressed, blown or tube-drawn at 900–1100 °C, then annealed near 420–450 °C.
What surface finishes work on Lead Glass (IEC G-500)?
Fire polish or acid polish (HF/H2SO4) for crystal brilliance; mechanical cerium-oxide polishing gives optical windows; can be coated with anti-reflective or anti-scratch films.
Lead Glass (IEC G-500) 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 |
|---|---|---|
| PbO55–65 % in radiation-shielding variant | 20 – 35 | 26 |
| K2O | 4 – 12 | 8 |
| Na2O | 2 – 9 | 5 |
| Al2O3 | 0 – 2.5 | 0.8 |
| CaO | 0 – 1.5 | 0.3 |
| BaOsometimes substituted for part of PbO | 0 – 3 | 0.5 |
| As2O3/Sb2O3fining agents | 0 – 0.5 | 0.2 |
| CeO2browning inhibitor in shielding glass | 0 – 1 | 0.3 |
| SiO2typically 55–65 % | balance | — |
Lead Glass (IEC G-500) CRYSTAL-30 — frequently asked
What is Lead Glass (IEC G-500) CRYSTAL-30 used for?
Lead Glass (IEC G-500) CRYSTAL-30 is typically used for crystal glassware, X-ray/radiation shielding windows, CRT/electron tube glass and electrical insulators. In short: best radiation-shielding glass; highest refractive index here; long lampworking range.
What is the tensile strength of Lead Glass (IEC G-500) CRYSTAL-30?
Lead Glass (IEC G-500) CRYSTAL-30 has a typical tensile strength of 45 MPa (6.53 ksi) — weaker than 56% of glass grades. Strength varies by condition: see the 3 listed tempers.
Is Lead Glass (IEC G-500) CRYSTAL-30 easy to machine?
Not especially — machinability is rated poor (15/100, worse than 54% of glass grades). Grind, core-drill and score with diamond tooling under flood coolant; anneal after heavy grinding and avoid edge chipping — no conventional cutting.
Can Lead Glass (IEC G-500) CRYSTAL-30 be welded?
Not weldable; joined by flame/lampworking or by glass-to-metal (Dumet, Ni-Fe) sealing thanks to the ~9 µm/m·K CTE match.
What surface finishes work on Lead Glass (IEC G-500) CRYSTAL-30?
Fire polish or acid polish (HF/H2SO4) for crystal brilliance; mechanical cerium-oxide polishing gives optical windows; can be coated with anti-reflective or anti-scratch films.
Can Lead Glass (IEC G-500) CRYSTAL-30 be formed, bent or molded?
Melts easily at 1300–1400 °C with a long working range; pressed, blown or tube-drawn at 900–1100 °C, then annealed near 420–450 °C.
What is the maximum service temperature of Lead Glass (IEC G-500) CRYSTAL-30?
Lead Glass (IEC G-500) CRYSTAL-30 is rated for continuous use to about 300°C (572 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- IEC 60672-1/-3 Ceramic and glass insulating materials — Part 3: Specifications for individual materials — IEC (1997)
- ASM Engineered Materials Handbook Vol. 4: Ceramics and Glasses — ASM International (1991)
- Radiation shielding glass RD 50 / lead glass properties — SCHOTT (2023)
- CDGM ZF-series high-lead optical glass data — CDGM (2023)
- ISO 719 / ISO 720 hydrolytic resistance of glass grains — ISO (2020)
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.