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MACOR®

Machinable Glass Ceramic (MGC)

Special Properties

  • Machinable with conventional metalworking equipment
  • Coefficient of thermal expansion close to many metals and sealing glass
  • High temperature resistance
  • Non-porous
  • Dimensionally stable
  • No outgassing
  • Odorless, opaque, white material
  • Excellent electrical insulation properties
  • Available as semi-finished bars, rods and sheets

Typical Applications

  • High precision workpieces
  • Contact holders, sockets, bushings, and feedthroughs
  • Aerospace industry
  • Substrates for field ion microscopes
  • Ultra-high vacuum and continuous vacuum applications
  • Medical devices
  • Laser cavity components
  • Insulators for electronic connectors
  • Welding nozzles
  • Bushing tubes
  • Mounting brackets
  • Laser alignment components

Related Ceramic Materials

  • SHAPAL™ Hi M-soft
    (Machinable aluminum nitride ceramics)
  • Al2O3
    (Alumina high-performance ceramics)

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MACOR® machinable glass ceramic from CORNING is a white, odorless, and opaque material consisting of 55 % MIKA and 45 % borosilicate glass. The high performance Small machined parts made of MACOR® from CORNING glass ceramic offers ideal properties for a wide range of industrial applications. MACOR® can be used to produce complex shapes and precise parts with tight tolerances. The glass ceramic can be CNC machined with conventional HSS tools commonly used for metal machining. As a result, expensive specialized machinery and diamond tooling are typically not required to machine MACOR® material. Learn more about the machining parameters of MACOR® in our Machining Guidelines.

Finished part made of MACOR® MGC
nullspacer Figure: A finished part with tight tolerances machined from MACOR® MGC

MACOR® can be used at temperatures of up to 800°C for long periods of time and can withstand up to 1000°C without load. In addition, the unique glass ceramic has zero porosity and is non-wetting. MACOR® does not deform or outgas allowing it to be used in vacuum environments. The material is an excellent insulator for high voltages at various frequencies. MACOR® sets an industrial standard for machinable glass ceramic that is difficult for other MGC materials to match. It is ideal for a wide range of applications in the aerospace, medical and semiconductor industries.

 

Semi-finished raw material

Our company stocks MACOR® as semi-finished sheets, rods, and bars (see table) with short lead times. These are the starting materials for complex shaped parts.

Components of MACOR® glass ceramic nullspacer

Send a request for custom parts made from original MACOR® machinable glass ceramic to your specifications.

 

To get a quote for semi-finished MACOR® materials or a finished MACOR® part with custom shape and dimensions according to your drawing, please click the button below:


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Specifications and Properties


Semi-finished MACOR® raw material:

MACOR® Rods

Diameter
(mm)
Lengths
(mm)
3 70
4 70
6 70
8 70
12,5 70
19 75, 150, 300
25 75, 150, 300
30 75, 150, 300
38 75, 150, 300
50 75, 150, 300

MACOR® Bars

Dimension
(mm × mm)
Lengths
(mm)
12,5 × 12,5 75, 150, 300
19 × 19 75, 150, 300
25 × 25 75, 150, 300
30 × 30 75, 150, 300
50 × 50 75, 150, 300

MACOR® Sheets

Size
l × w
(mm)
Thickness
(mm)
75 × 75 12,5, 19, 25, 30, 50
150 × 150 12,5, 19, 25, 30, 50
300 × 300 12,5, 19, 25, 30, 50

The MACOR® materials listed above are available in approximately one week or less. Larger dimensions may take longer. Please send us your request.

 

MACOR® MGC Machining Guidelines

Density

  • 2,52 g/cm3

Coefficient of Thermal Expansion

  • 74 × 10-7 / °C (-200–25°C)
  • 93 × 10-7 / °C (25–300°C)
  • 114 × 10-7 / °C (25–600°C)
  • 126 × 10-7 / °C (25–800°C)

Thermal Characteristics

  • Continuous operating temperature: 800°C
  • Max. operating temperature: 1000°C (no load)
  • Thermal Diffusivity: (25 °C): 7,3 × 10-7 m2/s
  • Thermal Conductivity: (25 °C): 1,46 W/m°C
  • Specific Heat (25 °C): 0,79 KJ / kg°C

Mechanical Characteristics

  • Porosity: 0 %
  • Young's Modulus: (25°C): 66,9 GPa
  • Poisson's Ratio: 0,29
  • Shear Modulus: (25°C): 25,5 GPa
  • Knoop Hardness: (100 g): 250
  • Modulus of Rupture: (25°C): 94 MPa
  • Compressive Strength: 345 MPa
  • Fracture Toughness: 1,53 MPa m0,5

Electrical Characteristics

  • Dielectric Constant: (25°C): 6,03 (1 kHz)
  • Dielectric Loss Tangent: (25°C): 4,7 x 10-3 (1 kHz)
  • Dielectric Strength: (25°C): 40 kV / mm
    (at 0,254 mm thickness)
  • Volume Resistivity: >1016 Ω-cm
Very small work pieces of MACOR® nullspacer MACOR® machinable glass ceramic allows the design of such tiny and intricate parts with high precision. For additional information, please contact us.


Composition of MACOR® Glass Ceramic

Substance approximate weight
percentage
Silicon oxide (SiO2) 46
Magnesium oxide (MgO) 17
Alumina (Al2O3) 16
Potassium oxide (K2O) 10
Boron oxide (B2O3) 7
Fluorine (F) 4

Chemical Properties

Medium

pH

Time
(h)

Temp.
(°C)

Weight loss
(mg/cm2)

5 % HCL
0,1
24 h
95 °C
ca. 100
0,002 N HNO3
2,8
24 h
95 °C
ca. 0,6
0,1 N NaHCO3
8,4
24 h
95 °C
ca. 0,3
0,02 N Na2CO3
10,9
6 h
95 °C
ca. 0,1
5 % NaOH
13,2
6 h
95 °C
ca. 10
H2O (water)
7,6
24 h
95 °C
ca. 0,01

All details and specifications provided here are mean reference values and are not guaranteed. Also, please consider our "Notes on Specifications".

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Last update: 14.03.2024