JGS1
Grade · default condition
GB JGS2, JGS3
JGS1 = far-UV grade, high OH, bubble-free
Pick for deep/far-UV optics and lamp envelopes needing transmission down to ~185 nm and freedom from bubbles and inclusions.
Values for the JGS1 condition
Other JGS1 tempers and conditions
JGS1 is listed in 3 conditions; see the grade overview at JGS1.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
UV/visible grade, flame-fused natural quartz | General-purpose UV–visible grade (from ~220 nm) at lower cost; a few bubbles and slightly higher metallic impurity than JGS1. | — | 48 | 0 | 740 HV | 1 W/m·K |
JGS1DefaultThis page Far-UV grade, high OH, bubble-free | Pick for deep/far-UV optics and lamp envelopes needing transmission down to ~185 nm and freedom from bubbles and inclusions. | — | 50 | 0 | 750 HV | 1 W/m·K |
IR grade, low OH, electrically fused | Choose when transmission through the near/mid-IR to ~3.5 µm is needed, or for the highest continuous service temperature (low OH raises viscosity). | — | 50 | 0 | 750 HV | 1 W/m·K |
What is JGS1?
JGS1 is JGS1 in the JGS1 grade — pick for deep/far-UV optics and lamp envelopes needing transmission down to ~185 nm and freedom from bubbles and inclusions. JGS1 has a tensile strength of 50 MPa (7.25 ksi), stronger than 59% of glass grades. Elongation at break is 0% and the elastic modulus is 72 GPa (10.4 Msi). JGS1 has a density of 2.2 g/cm³ (0.0795 lb/in³), lighter than 94% of glass grades. It melts at 1,713°C (3,115 °F).
Advantages
- Lightweight — 2.2 g/cm³ (0.0795 lb/in³), better than 94% of glass grades
- Good corrosion resistance — 95/100, better than 92% of glass grades
- High service temperature — 1,050°C (1,922 °F), better than 90% of glass grades
JGS1 properties
Typical room-temperature values for JGS1; 16 are specific to this condition. Other listed values are JGS1 reference data and may not represent this condition. Bars are the position among glass grades.
Physical5
JGS1 has a density of 2.2 g/cm³ (0.0795 lb/in³), lighter than 94% of glass grades. It melts at 1,713°C (3,115 °F).
Mechanical13
JGS1 has a tensile strength of 50 MPa (7.25 ksi), stronger than 59% of glass grades. Elongation at break is 0% and the elastic modulus is 72 GPa (10.4 Msi).
Thermal5
JGS1 is rated for continuous service to 1,050°C (1,922 °F). It conducts heat at 1.4 W/m·K (0.797 BTU/hr·ft·°F), better than 54% of glass grades. Thermal expansion is 0.55 µm/m·K (0.306 µin/in·°F).
Electrical5
JGS1 is an electrical insulator with a dielectric strength of 30 kV/mm (762 V/mil) and a resistivity of 1×10¹⁶ Ω·m.
Chemical & Environmental2
Corrosion resistance is excellent (95/100), better than 92% of glass grades.
Sustainability4
Producing a kilogram of JGS1 takes about 55 MJ of energy and emits 4.5 kg of CO₂ — more than 52% of glass grades. Typical recycled content is 0%.
Manufacturability3
JGS1's machinability is not recommended (12/100, worse than 68% of glass grades).
Common Calculations4
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with JGS1
Is JGS1 easy to machine?
Diamond grinding, core drilling, ultrasonic and laser/waterjet only — no conventional cutting; chip-free edges need bevelling and coolant flooding.
Can JGS1 be welded?
Joined by hydrogen-oxygen torch or plasma fusion welding at 1800–2000 °C; the joint must be flame-annealed near 1100 °C to avoid stress birefringence and cracking.
Can JGS1 be formed, bent or molded?
Hot-formed by flame/electric-furnace working above ~1700 °C (tube drawing, flaring, bending); no cold forming — the material is fully brittle at room temperature.
What surface finishes work on JGS1?
Lapped and pitch/CeO2 polished to λ/10 flatness and sub-nm roughness; HF etch removes subsurface damage, and AR/UV coatings adhere well to a clean fire-polished surface.
JGS1 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 |
|---|---|---|
| OHhydroxyl 50–1200 ppm for JGS1; <10 ppm for JGS3 | 0.01 – 0.12 | 0.06 |
| Almain metallic impurity | ≤ 0.01 | 0 |
| Na | ≤ 5×10⁻⁴ | 1×10⁻⁴ |
| Fe | ≤ 5×10⁻⁴ | 1×10⁻⁴ |
| Ca | ≤ 5×10⁻⁴ | 2×10⁻⁴ |
| Ti | ≤ 5×10⁻⁴ | 1×10⁻⁴ |
| SiO2vitreous silica | ≥ 99.98 (balance) | — |
JGS1 — frequently asked
What is JGS1 used for?
JGS1 is typically used for semiconductor process tubes, optical windows, lighting envelopes and lab glassware. In short: economical fused quartz; 1050 °C service temperature; graded transmission series.
What is the tensile strength of JGS1?
JGS1 has a typical tensile strength of 50 MPa (7.25 ksi) — stronger than 59% of glass grades. Strength varies by condition: see the 3 listed tempers.
Is JGS1 easy to machine?
Not especially — machinability is rated not recommended (12/100, worse than 68% of glass grades). Diamond grinding, core drilling, ultrasonic and laser/waterjet only — no conventional cutting; chip-free edges need bevelling and coolant flooding.
Can JGS1 be welded?
Joined by hydrogen-oxygen torch or plasma fusion welding at 1800–2000 °C; the joint must be flame-annealed near 1100 °C to avoid stress birefringence and cracking.
What surface finishes work on JGS1?
Lapped and pitch/CeO2 polished to λ/10 flatness and sub-nm roughness; HF etch removes subsurface damage, and AR/UV coatings adhere well to a clean fire-polished surface.
Can JGS1 be formed, bent or molded?
Hot-formed by flame/electric-furnace working above ~1700 °C (tube drawing, flaring, bending); no cold forming — the material is fully brittle at room temperature.
What is the maximum service temperature of JGS1?
JGS1 is rated for continuous use to about 1,050°C (1,922 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- GB/T 12442 (Optical quartz glass, JGS1/JGS2/JGS3) (2015)
- Fused Silica / Quartz Glass Material Properties (Suprasil, Infrasil, HOQ) — Heraeus Conamic (2023)
- HPFS 7980 Fused Silica Product Information — Corning (2022)
- 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.