Machinable Glass Ceramic (Macor Ceramic)

Machinable Glass Ceramic (also known as MGC & Macor Ceramic) is a polycrystalline composite material, white in its entire body. It is a glass ceramic material with synthetic mica crystallites as the main crystal phase. Macor-machinable ceramic combines the excellent electrical, thermal, and mechanical properties of advanced technical ceramics with the ease of machining using conventional metalworking tools. This eliminates expensive diamond grinding and subsequent firing, significantly reducing manufacturing time and costs.

At Great Ceramic, we offer high performance machinable glass ceramics (MGC), providing high quality Macor rods, Macor plates, Macor tubes and custom machined components to industries requiring superior performance, electrical insulation and thermal stability.

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Advantages of Macor Machinable Glass Ceramic

The most prominent feature of Macor's machinable glass-ceramic is its machinability, enabling it to meet high-precision technical requirements without the need for molds, allowing for direct molding and significantly shortening design and processing cycles. Consequently, Macor ceramics are often used in structural ceramic parts with complex shapes, high precision requirements, and difficult molding processes, such as thin-walled ceramics and ceramic threads.

Features: It can be turned, milled, drilled, tapped, and other operations using common metalworking tools, achieving high-precision machining.

Applications: Suitable for complex structural components such as insulation pads, thermal insulation pads, insulation brackets, and heat-resistant brackets in various mechanical equipment.

Features: It exhibits excellent high-temperature electrical insulation performance, with an electrical breakdown strength of up to 40 kV/mm.

Applications: Widely used in various electrical equipment, such as key components of lightning rods.

Features: It has a wide operating temperature range (-200°C to +800°C). Its mica crystal structure provides excellent thermal shock resistance, while its low thermal expansion coefficient ensures dimensional stability.

Applications: Suitable for welding fixtures, optical glass secondary molding molds, and other applications.

Features: Its extremely low outgassing rate makes it suitable for high vacuum environments.

Applications: Widely used in vacuum equipment and vacuum coating brackets in the photovoltaic industry.

Features: Made of all-inorganic materials, it resists aging and deformation, and offers excellent corrosion resistance to various organic solvents, acids, and alkalis, surpassing that of ordinary ceramics and polytetrafluoroethylene.

Applications: Used in key components in the chemical industry, such as rods and slings for crude oil and seawater desalination electrodes.

Features: Excellent electromagnetic properties.

Applications: Coil spools for missile gyroscopes, etc.

Features: Self-lubricating and free of metal particles. Its specific gravity is approximately one-third that of ordinary steel, lighter than aluminum, and has extremely low water absorption.

Applications: Vanes for rotary vacuum pumps, etc.

Precautions for use

Macor machinable glass ceramics are easily affected by halogen acids such as HCl (hydrochloric acid). Tests showed that 2.52 grams (1cc) of the glass ceramic sample was exposed to hydrochloric acid with a pH of 0.1 and lost 100 mg (3.96%) within 24 hours. When exposed to sodium hydroxide with a pH of 13.2, it lost 0.396% in 6 hours. When it exceeds 600°C (in a vacuum), fluorine will precipitate, which is manifested as boron trifluoride or hydrofluoric acid.

Industry Applications

Macor ceramic, with its excellent machinability, high thermal stability, electrical insulation, and resistance to vacuum and chemicals, is widely applied across industries—from serving as high-temperature fixtures and insulators in aerospace, semiconductor, and electronics, to radiation-resistant components in medical and nuclear technology, and precision-engineered parts in industrial machinery—making it a versatile material that bridges the gap between traditional ceramics and easily machined engineering materials.

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Used for sensor housings, thermal insulators, and windows due to its stability and RF transparency.

Essential for wafer processing components, plasma etch fixtures, and insulators where purity and vacuum integrity are critical.

Fabricated into custom insulators, beamline components, and vacuum chamber parts in particle accelerators.

Used in MRI equipment, X-ray components, and sterilizable surgical instrument parts for its non-magnetic and bio-inert properties.

Serves as fixtures, reflectors, and insulators in high-temperature furnaces and lighting systems.

Ideal for creating custom measurement tools, optical breadboards, and alignment fixtures that require thermal and electrical stability.

Available grades of macor glass ceramics

"Same Reliability, Smarter Choice."

Great Ceramic offers high-performance Macor machinable glass ceramic, also known as MGC. Our MGC shares key properties with Macor ceramic—excellent thermal insulation, electrical resistance, and machinability—ensuring seamless replacement in demanding applications. Furthermore, our MGC offers significant cost advantages, faster delivery, and flexible supply.

Great Ceramic combines material supply with CNC machining services to deliver ready-to-use custom parts from rods, sheets, or tubes, all with tight tolerances and smooth surfaces. It is widely used in aerospace, semiconductor, medical, and vacuum technology fields.

Our MGC offers the same key properties as Macor ceramic — excellent thermal insulation, electrical resistance, and machinability — ensuring seamless substitution in demanding applications.

Imported Macor often comes with high pricing and logistics costs. Great Ceramic delivers more competitive pricing without compromising quality, helping you reduce project budgets.

Say goodbye to long overseas lead times. With local production capacity and inventory, we provide shorter lead times and flexible order volumes — from small prototypes to large-scale runs.

Unlike standard suppliers, Great Ceramic combines material supply + CNC machining service, delivering ready-to-use custom parts from rods, sheets, or tubes — all with tight tolerances and smooth finishes.

Trusted by clients in aerospace, semiconductor, medical, and vacuum technology, our MGC ceramics are already replacing imported Macor in critical projects worldwide.

Composition of Macor machinable glass ceramics

Machinable ceramic is a composite material made of fluorophlogopite in a borosilicate glass matrix at a ratio of 45/55, respectively. Its ingredients are as follows:

  • 46% silicon dioxide (SiO2)Machinable ceramic microstructure
  • 17% Magnesium Oxide (MgO)
  • 16% alumina (Al2O3)
  • 10% potassium (K2O)
  • 7% boron (B2O3)
  • 4% fluorine (F)
Composition of Macor machinable glass ceramics

Key Properties of Macor Ceramic

Great Cerramic's high-performance MGC offers similar high-temperature, electrical insulation, and machinability properties to macor, but with better cost-effectiveness, faster delivery, and customizable precision parts.

Below we list the typical properties of MGC, Macor ceramics, and hexagonal boron nitride ceramics (HBN) to help engineers better compare the differences in materials and find suitable applications.

The following values are typical material properties and may vary depending on product configuration and manufacturing process. For more details, please feel free to contact us.

Mechanical Properties

The mechanical properties of MGC & Macor ceramics are characterized by "medium strength, easy processing, high dimensional stability, moderate hardness and light weight".

Properties Unit MGC Macor HBN
Colour —— White White White
Density g/cm³ 2.48 2.52 2.0
Hardness GPa 2.0 2.5 0.04
Compressive Strength MPa 508 345 100
Flexural Strength MPa 91.5 94 30
Fracture Toughness MPa・m1/2 —— 1.53 ——
Modulus of Elasticity GPa 65 66.9 71
Poissons Ratio —— —— 0.29 ——

Thermal Properties

The thermal properties of MGC & Macor ceramics are characterized by "high temperature stability, low thermal expansion, low thermal conductivity, thermal shock resistance and thermomechanical stability"

Properties Unit MGC Macor HBN
Maximum Use Temperature ℃(No load) 800 800 850
Thermal Conductivity @ 20°C W/(m・K) 1.71 1.46 ＞30
Thermal Expansion a at 25–200°C 1 x 10-6/°C 7.38 9.3 ＞1.8
Specific Heat KJ/kg・℃ —— 0.79 0.81

Electrical Properties

The electrical properties of MGC & Macor ceramics are characterized by "high insulation strength, high resistivity, low dielectric constant, thermal stability and low dielectric loss"

Properties Unit MGC Macor HBN
Dielectric Constant 1MHz 5.7 6.03 4.0
Dielectric Strength ac-kV/mm 43.4 45 79
Volume Resistivity @ 25°C Ω・cm ＞1016 ＞1017 ＞1013

Macor ceramic parts application cases

Macor machinable glass ceramics, with their unique properties, including excellent machinability, high electrical insulation, high temperature resistance, and zero porosity, are ideal for a variety of precision and demanding applications. The following are the most common and influential application cases of MGC & Macor products in different fields:

Used in electronic and semiconductor devices, they provide precise dimensional control and excellent electrical insulation.

Serves as an insulator in power systems requiring high dielectric strength.

Used in high-vacuum systems, its zero porosity ensures a hermetic seal, preventing gas leaks.

Used in laser equipment as cavities, mirror brackets, and insulators, its low coefficient of thermal expansion helps maintain optical path stability.

Used as furnace insulators, thermocouple protection tubes, and sample holders, capable of stable operation at temperatures up to 800°C.

Used in components that require precision, non-porous properties, and sterilizability, such as in surgical instruments or analytical equipment.

Because it is easy to process with standard tooling, Macor is a preferred material for the rapid production of complex prototypes and custom precision parts.

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Macor Ceramics Manufacturing & Machining

At Great Ceramic, we utilize standard metalworking tools and techniques, such as CNC machines, lathes, milling machines, and drill presses, to cut, drill, tap, and shape Macor machinable glass-ceramics, eliminating the need for expensive diamond grinding or sintering post-processing. This significantly shortens manufacturing cycles and reduces costs, while still achieving micron-level tolerances and meeting the stringent precision and surface quality requirements of complex structural components.

Leveraging years of technical experience and advanced equipment, we not only offer standardized Macor parts such as Macor rods, plates, and tubes, but also customize complex structural assemblies and high-reliability products to meet specific customer needs, helping customers apply Macor ceramics to a wide range of industrial applications.

Precision Ceramic CNC Machining

CNC Grinding & Milling

CNC milling, turning, and grinding to micron-level tolerances.

Ceramic Grinding & Polishing

Lapping & Polishing

Surface polishing for smooth finishes and optical-grade surfaces.

Technical Ceramic Laser Cutting

Ceramic Laser Cutting

Laser drilling and cutting for complex geometries.

Ceramic and Metal Brazed Assemblies

Metallization & Welding

Metallization (Mo/Mn, W) for ceramic-to-metal brazing.

Frequently Asked Questions

Macor ceramic machining can be done with conventional metalworking tools, such as carbide drills, taps, and milling cutters. You should use a water-soluble coolant to minimize chipping and dust.

Glass-mica ceramic machining refers to the process used for materials like MACOR®, which is a composite of glass and mica crystals. The process is the same as for other machinable glass ceramic materials, utilizing standard tooling and techniques.

Most ceramics are extremely hard and brittle, making machining ceramic difficult and requiring specialized diamond tooling. However, machinable ceramics like MACOR® are specifically engineered to be processed with standard tools.

Unlike Macor, alumina is a hard, traditional ceramic. It cannot be machined with standard tools. How to machine alumina ceramic requires a post-sintering process using specialized diamond grinding wheels and tools to achieve the final shape and tolerances. Learn More →

Macor ceramics and BN+AlN composite boron nitride ceramics are both machinable ceramics. They both possess excellent machinability and can be processed with standard tools like metal, significantly reducing manufacturing costs and time.

However, despite their similarities, their core properties and applications differ significantly.

Major Differences

Macor ceramics: Macor is a unique glass-ceramic composite material composed primarily of fluorphlogopite and borosilicate glass. Its core advantages lie in its ease of processing, excellent electrical insulation properties, and extremely low outgassing. Macor exhibits excellent dimensional stability at high temperatures, exhibits no creep or deformation, and matches the thermal expansion coefficient of most metals and sealing glasses.

BN+AlN composite boron nitride ceramics: This is a composite material composed of boron nitride (BN) and aluminum nitride (AlN). Its most prominent features are its extremely high thermal conductivity and excellent electrical insulation. The addition of AlN significantly improves the material's thermal conductivity and mechanical strength, while BN imparts excellent machinability and self-lubrication.

Typical Applications

Macor ceramics: Due to its thermal insulation and vacuum properties, it is primarily used in applications requiring precise dimensional control, electrical insulation, and high vacuum environments. Examples include insulators in space probes, high-voltage feedthroughs, brackets and sample holders in vacuum chambers, and precision components in medical and laser equipment.

BN+AlN composite boron nitride ceramics: Due to their high thermal conductivity and electrical insulation, they are primarily used in applications requiring efficient heat dissipation. Examples include heat sinks in semiconductor production equipment, substrates for high-power electronic devices, high-voltage insulators, and precision components that must withstand thermal shock and corrosion.

Macor ceramic has a maximum operating temperature of 1000°C (1832°F), which refers to the peak temperature under no load.

Its maximum continuous operating temperature is 800°C (1472°F).

Due to its excellent thermal stability and low coefficient of thermal expansion, Macor ceramic does not deform or creep at high temperatures, making it an ideal insulating and structural material for many high-temperature applications.

If other high-temperature ceramic materials are needed, please view our performance comparison chart.

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Silicon Nitride

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Why Choose Great Ceramic's MGC

  • Engineering Expertise – Great Ceramic focuses on precision ceramic machining, ensuring complex parts are manufactured to tight tolerances.

  • Material Performance – Our MGC combines excellent thermal insulation, electrical resistance, and chemical stability, comparable to branded Macor ceramics.

  • Design Flexibility – Available in rods, sheets, and tubes, with the ability to produce customized CNC-machined components.

  • Cost & Lead Time Advantage – Faster prototyping, reduced machining cost compared to traditional ceramics, and shorter delivery cycles.

  • Industry Reliability – Trusted across aerospace, semiconductor, medical, and vacuum industries for components that require stability and machinability.

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