Custom fused silica fabrication · Made to drawing · No MOQ

Custom quartz glass fabrication is the manufacture of high-purity fused silica components to a customer CAD drawing, dimensioned sketch, or sample, rather than from a fixed catalogue of sizes. If it can be drawn, FGQuartz can machine or form it.

Using in-house CNC diamond machining, oxy-hydrogen flame forming, welding, fire polishing, and annealing, FGQuartz builds non-standard tubes, flanged and multi-port vessels, optical windows, laboratory glassware, heater chambers, wafer boats, and replacement parts, from a single prototype to production, with no minimum order quantity. Drawings in DXF, STEP, IGES, or PDF are accepted, and a sketch, sample, or written functional description is enough to start.

Quick answer

Making fused silica parts to your drawing when a standard catalogue size will not fit: a non-standard dimension, an added feature such as a flange or port, a specific optical or purity grade, a multi-part welded assembly, or a reproduction of a legacy part.

Key takeaways

• No minimum order quantity: single prototypes are a normal request. Free engineering DFM review and NDA protection are available.
• Simpler custom components typically ship in 7–14 days; complex custom assemblies take about 3–6 weeks.
• Two fabrication routes work together: cold processing (CNC machining, grinding, polishing) and thermal processing (flame forming, welding, annealing).
• Grades include natural fused quartz, synthetic fused silica, JGS1 / JGS2 / JGS3, and opaque fused silica. Quartz is not suitable for HF, hot concentrated phosphoric acid, or hot strong alkalis.

Written by the FGQuartz Engineering Team · Updated November 2026

On this page: What is custom fabrication · Product families · Capability matrix · Fabrication routes · Examples · Typical requests · Materials and grades · Tolerances and quality · How to order · FAQ and quote

Lead time depends on size and drawing complexity; the quote confirms the schedule.

Overview

Custom quartz glass fabrication covers everything from a non-standard length of tube, through multi-port reactor vessels with precision-machined flanges, optical-grade polished windows, and flame-welded gas inlet assemblies, to one-off replacement parts for equipment whose original supplier no longer supports it. It is essential whenever application geometry, dimensional constraints, or equipment interfaces cannot be met by any stock product.

At FGQuartz, custom does not mean a narrow menu of approved variations. The engineering and production teams start from your drawing or functional requirement and work out the right combination of raw material, forming process, and machining operations to build it, whether or not it resembles anything made before.

Fused silica (amorphous silicon dioxide) combines high-temperature stability, near-zero thermal expansion, broad UV-to-IR optical transmission, and chemical inertness to most industrial process environments. That makes custom quartz components hard to replace in high-temperature, chemically aggressive, or optically critical applications where polymers, metals, and ordinary glasses fail. Fused silica can also be ground, drilled, turned, and polished with diamond tooling to the geometrical accuracy that precision process equipment demands. Background: What is quartz glass? and quartz glass vs borosilicate glass. Typical values are on the Technical Specifications page.

• A non-standard outer diameter, wall thickness, or length not found in any catalogue.
• Flanges, ports, closed ends, or other fabricated features on a tube or vessel.
• Complex hollow geometries: tees, crosses, multi-arm manifolds, bent sections.
• Optical elements such as windows or cuvettes with specific dimensions or surface quality.
• Several quartz components assembled into one integrated unit.
• A broken or discontinued part with no drawing to reproduce.
• A specific purity grade, optical grade, or trace-impurity limit.
• A part that combines product lines, such as a tube with a crucible-style closed end or a plate with wafer-boat-style slotting.
• Parts outside the standard pages: labware, heater chambers, optical assemblies, or fiber-related components.

Product families

The standard product pages cover the main product lines, but fabrication is not limited to them. If it can be made from fused silica, the engineering team will evaluate it.

If your requirement does not fit a row, describe the function it must perform and the engineering team will work out how to build it in fused silica.

Capability matrix

Customization is several independent dimensions that combine in almost any way. The table lists every axis.

In practice most inquiries are one combination of these rows, for example: a synthetic JGS1 tube, 45 mm OD, with two flanged ports and one closed dome end, optically polished on the internal bore, quantity 12. If you can describe a requirement like that, or attach a drawing, the engineering team can evaluate it directly.

Fabrication routes

Complex custom projects use two complementary routes, and advanced parts often need both to hold tolerance and reach a complex geometry.

Oxy-hydrogen flames soften, bend, fuse, and seal fused silica, which builds complex hollow structures and seamless joints. This route makes shapes that have no straight-line CNC path at all: curves, branches, and sealed hollow chambers.

Key capabilities

• Flame welding for tube-to-tube and tube-to-flange joints.
• Tube bending, stretching, and diameter expansion or reduction.
• Domed or flat end-sealing and side-arm additions.
• Fire polishing for clean, particle-free surfaces.
• Controlled annealing to relieve localized weld stress.

Typical components

• Multi-chamber reactor vessels and chemical baths.
• Sealed thermocouple protection tubes and heating envelopes.
• Multi-port gas manifolds (tees, crosses, Y-joints).
• U-shaped, L-shaped, and serpentine process tubes.

Multi-axis CNC centers and diamond tooling reach micro-tolerances and geometries that thermal forming alone cannot. This is the route for anything that needs a flat face, a precise hole, a thread, or an optically polished surface.

Key capabilities

• CNC turning and centerless grinding.
• Multi-axis milling of slots, pockets, and freeform profiles.
• Diamond core drilling, through and blind holes.
• Internal and external thread machining, edge chamfering.
• Lapping and optical-grade polishing to a controlled Ra.

Typical components

• Process tubes with machined steps, tapers, or O-ring grooves.
• Solid support rods, push paddles, and isolation elements.
• Optical windows, cuvettes, and vacuum substrates.
• Wafer boats with accurate pitch slotting, and CNC-machined flanges and base plates.

Examples

Every custom part is different, so no single product photo represents this page. These examples show the process and the range of output.

Flame-worked fused silica assemblies: funnels, joints, and multi-port fittings.

Custom fused silica parts: coils, bends, crucibles, and vessels from one fabrication set.

Multi-port fused silica process vessels with top connections for laboratory and pilot systems.

CNC-machined fused silica flat parts: plates, frames, grids, and complex outlines cut to drawing.

Typical requests

It is often easier to recognize your own situation in a scenario than in a spec sheet. These are illustrative requests, not a list of fixed products.

Materials

Custom fabrication starts with the right base material. Choosing it up front avoids paying for purity you do not need, or under-specifying a material for an optically or chemically demanding process.

Not sure which grade fits? Describe the operating temperature, chemical exposure, and any wavelength requirement and the engineering team will recommend one. For wavelength-driven choices, see optical quartz glass.

Quality

Not every feature needs the same precision, and tight tolerances everywhere only add cost. During DFM review the engineers identify which dimensions are functionally critical (sealing faces, optical surfaces, mating interfaces) and which can run to standard commercial tolerance, so you pay for precision only where it matters.

Finished components are verified under the ISO 9001 quality system using coordinate measuring machines (CMM) for dimensional accuracy, polarizing microscopy for residual stress in welds and thermally formed sections, and surface metrology for optical-grade parts. For critical or first-run OEM designs, a First Article with a dimensional metrology report can be produced before volume production. Certificates of conformance and, where required, non-disclosure agreements are available on request.

Process

The same workflow applies whether you order a single R&D prototype or a volume OEM program.

Manufacturer

Procurement questions

Keep reading

Get in touch

However you plan to make it, start the conversation. Useful to include, but none of it is mandatory:

• What the part is for and how it is used
• A drawing, sketch, photo, or the old part
• Operating temperature and the chemicals or gases involved
• Size limits, finish, or optical grade if relevant
• Quantity: one prototype or a production run

Email: info@fgquartz.com
Location: Lianyungang, China
Reply: typically within 24 business hours