When you need CNC machining quartz glass — whether drilling holes in diffusion furnace tubes, milling flanges, cutting slots in boats or producing complex 3D shapes on plates and rods — your biggest concerns are always edge chipping, sub-surface micro-cracks, dimensional deviation after annealing and particles generated during machining. The solution is diamond tooling only, optimized low-stress parameters, multiple intermediate stress-relief steps and final fire polishing to heal all micro-damage. With 25 years of daily CNC machining quartz glass in our dedicated workshop (from simple holes to full 5-axis complex parts), we know that one wrong parameter can ruin an expensive blank. In 2025 precision requirements are higher than ever — correct CNC machining quartz glass achieves ±0.02mm tolerance while keeping the material completely stress-free and particle-free. Here is all the practical experience from our CNC department.
Why CNC Machining Quartz Glass Is Completely Different
Quartz glass is extremely hard (Mohs 7) and brittle with almost zero thermal expansion — standard metal machining methods cause immediate cracking or chipping.
Unique Challenges
Only diamond tools work; any overheating creates micro-cracks that open later at high temperature.
Material Behavior
All removed material becomes fine powder — perfect coolant and dust extraction are mandatory.
Our CNC Capability
5-axis CNC centers dedicated exclusively to quartz, diamond tooling, high-pressure through-tool coolant and in-process annealing options.
Key Parameters for CNC Machining Quartz Glass in 2025
These are the tolerances and finishes we deliver every day.
Dimensional Tolerances
Hole diameter ±0.02mm, flatness 0.01mm, position accuracy ±0.03mm.
Surface & Edge Quality
Machined Ra 0.5-1.5μm, edge chipping <50μm (before fire polishing).
Typical Parameter Table (Our Standard Range)
| Parameter | Achievable Specification |
|---|---|
| Hole Diameter Tolerance | ±0.02mm |
| Flatness (machined face) | 0.01mm |
| Position Accuracy | ±0.03mm |
| Minimum Wall Thickness | 1mm (safe) |
| Smallest Hole Diameter | Φ0.5mm |
| Maximum Workpiece Size | 1200×600×300mm |
Recommended Features by Application
Different parts require different machining strategies.
Diffusion Furnace Tubes & Flanges
Multi-start holes, O-ring grooves — ultra-slow feed and multiple rough/finish passes.
Quartz Boats & Wafer Carriers
Deep slots, thin walls down to 1.5mm — small-diameter diamond ball mills.
Optical Windows & Plates
Countersunk holes, stepped surfaces — 5-axis simultaneous machining.
Custom 3D Parts
Bell jars with ports, manifolds — full 5-axis with in-process stress relief.
Critical Steps to Prevent Damage
Follow these and failure rate drops to near zero.
Tooling & Parameters
Diamond tools only, 8000-20000 RPM, feed 50-300mm/min, depth ≤0.1mm per pass.
Coolant System
High-pressure deionized water through-tool coolant — no thermal shock, all dust removed instantly.
Stress Management
Intermediate annealing for deep cuts, full final annealing before fire polishing.
Our Complete CNC Machining Quartz Glass Workflow
Send your drawing — we follow this process daily.
Seven Main Steps
- Drawing review & machinability analysis
- Tool path simulation & stress prediction
- Rough machining with stock
- Intermediate annealing if required
- Finish machining to final tolerance
- Full stress-relief annealing
- Final fire polishing + ultrasonic cleaning + inspection
Common Features & Process Table
| Feature | Recommended Tool | Key Parameter | Post-Process |
|---|---|---|---|
| Holes <Φ5mm | Diamond drill | Peck drilling | Fire polish inside |
| Flanges & Grooves | Diamond end mill | Light finishing pass | Fire polish edges |
| Thin Walls/Slots | Small ball-nose mill | <0.05mm depth | Mandatory annealing |
| Complex 3D Surfaces | 5-axis diamond barrel | Constant engagement | Full fire polishing |
Eight Most Common Failures (And How to Avoid Them)
- Edge chipping >100μm
- Sub-surface cracks opening at high temperature
- Dimensional drift after annealing
- Hole position error >0.1mm
- Thin wall cracking during machining
- Particle contamination from poor coolant
- Surface burning from dull tool
- Delayed breakage days after machining
FAQ – CNC Machining Quartz Glass
Q1: Can you drill holes smaller than 1mm?
A: Yes — down to Φ0.5mm is routine.
Q2: Is fire polishing always done after CNC?
A: Yes for particle-critical parts; optional for structural only.
Q3: What file formats do you accept?
A: STEP, IGES, DXF, PDF — 3D preferred.
Q4: How thin can remaining walls be?
A: Safely 1mm, thinner with special fixturing.
Q5: Can you machine threads?
A: Both external and internal threads can be used.
Q6: Do you provide inspection reports?
A: Full dimensional report + photos + fire-polishing verification included.
Q7: Can you combine CNC and flame forming?
A: Yes — our specialty for best surface and precision.
Welcome to contact us now for professional CNC machining quartz glass advice and precision custom solutions.
