Description
Quartz glass tubes cover straight round and square tubing in fused quartz / fused silica, specified by OD, ID, wall thickness and length. This page holds the dimensional range, tolerance data, end processing and fabrication capabilities that apply to quartz tubing generally, together with the tube-format variants below.
Furnace & diffusion tubes, UV & lamp tubes, spiral / helical / U-shaped tubes and gauge & sight tubes are treated as independent products because each has its own process-specific parameter set and application fit.
Tube Types
| Tube Type | Specification Basis |
|---|---|
| Fused (Clear) Tubes | Standard clear fused quartz in round or square form; specified by OD / ID / wall / length. |
| Large & Thick-Wall Tubes | OD up to 500 mm; wall thickness up to 15 mm. Practical wall thickness increases with tube diameter and fabrication route. |
| Multi-Bore Tubes | Multiple parallel bores in one quartz body; hole count, bore diameter and pitch specified for the required cross-section. |
| Square Tubes | Specified by outer width / height, wall thickness, inner opening and length. |
| Opaque Tubes | Milky-white fused quartz with a light-scattering bubble-bearing structure; supplier-stated OD range 1–200 mm. |
Dimensions
| Parameter | Range |
|---|---|
| OD | 2–500 mm |
| Wall Thickness | 0.5–15 mm |
| Length | 5–3000 mm; longer lengths by tube-to-tube welding |
| Cross-Section | Round standard; square profiles available |
| ID | For round tubes: OD minus 2 × wall thickness |
Tolerance
| Wall Thickness | OD Tolerance |
|---|---|
| 1–3 mm | ±0.10–±0.15 mm |
| 3–5 mm | ±0.15–±0.20 mm |
| 5–10 mm | ±0.20–±0.30 mm |
| 10–15 mm | ±0.30–±0.50 mm |
Chamfer: ±0.10–±0.30 mm. Arc / angle: 1°–3°. Finished length tolerance is selected according to tube length and end-processing method.
End Processing
Cutting — Precision cut-to-length ±0.5 mm; scribe-and-break cutting; wet cutting for 3–13 mm OD small-bore tubing and up to 150 mm OD large-bore tubing; angle cutting.
Grinding — OD cylindrical grinding; ID grinding; CNC grinding.
Fire Polishing — Flame edge / end polishing after cutting or grinding.
Fabrication Services
Drilling — Mechanical / diamond drilling to Ø0.8 mm minimum with ±0.02 mm tolerance; diamond core drilling with ID-to-OD concentricity to ±0.003 in; laser drilling with hole diameters ≤1 µm.
Bending — Flame / hot forming; spiral and helical coil forming; U-shape bending; CNC-guided coil forming with programmable pitch and radius. Coil diameter, pitch and bend radius are controlled as formed-geometry parameters.
Sealing — Closed-end sealing; pinch sealing; quartz-to-metal sealing with metallized / graded transition; conical and ball-and-socket ground joints; compression flange seals with O-ring and KF-port-compatible interfaces.
Quartz Welding — Hydrogen-oxygen flame fusion welding; tube-to-tube, tube-to-flange, tube-to-plate and branch-port welding; flame or furnace annealing after welding where required.
Flange Options — Single-end flanged tube; both-ends flanged tube; conical ground joint; ball-and-socket ground joint; externally threaded tube connection; compression flange with KF-port-compatible interface.
Opaque Tube Properties
| Property | Opaque / Milky Quartz Tube |
|---|---|
| Base Material | SiO₂ ≥99.9% purity, fused into a bubble-bearing matrix that produces the milky, light-scattering appearance. |
| Long-Wave IR Transmittance | >70%; the material absorbs shorter-wave IR below about 4 µm and re-radiates absorbed energy as heat. |
| Operating Temperature | Supplier-stated continuous service up to 1050–1100°C; short-duration figures up to 1300–1450°C depend on grade, geometry and thermal loading. |
| Thermal Shock | One supplier cites repeated transfer from 900°C to 0°C water without cracking; this is grade- and geometry-specific rather than a universal bare-tube rating. |
| OD | 1–200 mm supplier-stated custom range; wall thickness and length selected for the required geometry. |
Material Grades
| Grade | Process | OH Content | Notes |
|---|---|---|---|
| Type I | Electrically fused | <10–30 ppm | GE214 / HSQ100 / PH300 / RQ200 |
| Type II | Flame-fused | ~150 ppm | Herasil-1 |
| Type III | Synthetic, flame hydrolysis | 200–1300 ppm | Suprasil 1 / 2 / 311 / 312 |
| Type IV | Synthetic, plasma / anhydrous fusion | <1–5 ppm | Suprasil 300 |
| JGS1 | — | ~1200 ppm | Transmission 0.17–2.10 µm; maximum blank <200 mm |
| JGS2 | — | ~150 ppm | Transmission 0.26–2.10 µm (Tavg >90%); maximum blank <300 mm |
| JGS3 | — | ~5 ppm | Transmission 0.185–3.50 µm (Tavg >85%); maximum blank <200 mm |
| Opaque / Milky | — | — | Appearance / thermal-radiation grade; not classified by OH content in the same way as clear optical quartz. |
Tube Selection
| Type | Independent Parameter | Typical Driver |
|---|---|---|
| Fused / Large & Thick-Wall / Multi-Bore / Square / Opaque (this page) | OD / ID / wall / length / cross-section | General tubing without process-chamber, spectral, coil or gauge-specific requirements |
| Furnace & Diffusion Tubes | Hot zone / ports / flange / boat clearance | Semiconductor diffusion, oxidation and CVD process chambers |
| UV & Lamp Tubes | Quartz grade / spectral cutoff | UV curing, excimer, germicidal and ozone-control lamp tubing |
| Spiral / Helical / U-Shaped Quartz Tubes | Coil diameter / pitch / bend radius | Heat exchange, fluid routing and custom formed geometry |
| Quartz Gauge & Sight Tubes | Interface / viewing area / installed assembly condition | Level gauges, sight glasses and replacement tubes |