Product Overview

Custom sapphire spacers—also known as sapphire shims or sapphire washers—are precision–machined components made from single-crystal aluminum oxide (Al₂O₃, 99.99%). These spacers are designed for applications that demand high mechanical strength, dimensional stability, and excellent resistance to chemicals, heat, and wear.

Unlike optical-grade sapphire windows, these spacers are supplied in an unpolished finish, making them ideal for structural, mechanical, and thermal support rather than optical transmission.

Sapphire’s Mohs hardness of 9 and its outstanding thermal and chemical durability make unpolished spacers a robust choice for semiconductor tools, precision instruments, and special fixtures where long-term reliability is essential.

Key Features

• Unpolished Finish
  Surface is lapped or ground without optical polishing; suitable for non-optical structural applications.

• Ultra-High Hardness
  Mohs 9 hardness provides excellent wear resistance compared with glass, quartz, or ceramics.

• Exceptional Mechanical Strength
  High compressive strength and stiffness ensure stability under load.

• Thermal Stability
  Working temperature up to 1600°C in air and 2000°C in vacuum or inert environments.

• Chemical Resistance
  Inert to most acids, alkalis, plasma, and solvents—ideal for harsh industrial environments.

• Customizable Shapes
  Available in discs, rings, rectangles, squares, stepped shapes, and complex geometries.

Manufacturing Process (Unpolished Type)

1. Crystal Cutting – Slicing from high-purity synthetic sapphire boules (C-plane / A-plane / R-plane available).

2. Shaping & CNC Machining – Outer diameter, inner diameter, and thickness customized to drawing.

3. Grinding / Lapping – Achieve flat or semi-flat unpolished surface finish.

4. Chamfering or Edge Smoothing – Optional to prevent chipping.

5. Cleaning & Inspection – Final dimensional checks and debris removal.

Typical Applications

• Semiconductor equipment – Spacers for wafer carriers, furnace boats, plasma chambers.

• Precision machinery – High-load, high-wear shims and gap-adjustment components.

• Opto-mechanical assemblies – Structural spacers around optical components.

• High-temperature fixtures – Support pieces in thermal processing tools.

• Chemical-resistant assemblies – Used where polymers or metals would degrade.

• Vacuum instruments – Non-outgassing, stable, and extremely durable.

Available Specifications

(Customizable according to drawings)

• Outer Diameter: 2–200 mm

• Inner Diameter: As required

• Thickness: 0.1–20 mm

• Shape: Round / Square / Ring / Rectangle / Slotted / Custom

• Surface: Unpolished (ground / lapped), single-side or double-side

• Tolerance: ±0.02–±0.1 mm depending on size

• Crystal Orientation: C-plane (0001) standard; A/R-plane optional

Why Choose Sapphire Instead of Ceramic or Quartz?

Sapphire spacers maintain precision and rigidity even after long-term exposure to plasma, heat, or mechanical stress.

FAQ

Q1: What is the surface roughness of unpolished sapphire spacers?
A: Typically Ra 0.4–1.2 µm (varies by grinding process). Optical polish is not applied.

Q2: Can you produce both single-side and double-side unpolished surfaces?
A: Yes. Both sides can be ground, or one side can remain semi-processed.

Q3: Are custom drawings supported?
A: Absolutely. We support DXF, PDF, STP, SolidWorks files, and complex shapes.