Macor® Machinable Glass Ceramic

Ceramic Substrates & Components Limited has been a leading official Corning inc. Macor machinable glass ceramic distributor and supplier for over 10 years and therefore has built up considerable expertise in the applications of Macor along with techniques to machine the material into complex shapes. We are continously looking to improve our manufacturing techniques and procedures.

We use CNC machines for accuracy and repeatabilty of the components and are able to accept customers own .dxf drawing files for directly loading into the machines.  We will of course supply bars and plates or even complete Maxi Slabs (approx. 355 X 330 X 57) and large rods (3″ diameter X 12″ long), these being the two original forms of the raw material, for customers to machine their own components. We have noticed that over the years that customers who originally purchased the raw material for machining their own components have subsequently returned for us to manufacture the finished components given our level of expertise and familiarlarity with Macor.

Macor is very popular with Engineers and Universities as an “R & D” material as it lends itself to modification using conventional metalworking tools.

We have a dedicated Macor website which has a wealth of additional information.

Macor® Features

  • Machinable with ordinary metalworking tools
  • Macor® allows fast turnaround, no post firing required
  • Holds tight tolerances, up to 0.0005in. (0.013mm)
  • Withstands high temperature, up to 1000°C (no load)
  • Macor® is clean, no out gasing and zero porosity.

Corning Macor machinable glass ceramic

Machinable Glass Ceramic


Macor® (machinable glass ceramic) has a continuous use temperature of 800°C and a peak temperature of 1000°C. Its coefficient of thermal expansion readily matches most metals and sealing glasses. It is non-wetting, exhibits zero porosity, and unlike ductile materials, won’t deform. It is an excellent insulator at high voltages, various frequencies and high temperatures. And, when properly baked out, it won’t outgas in vacuum environments.


Machining tolerances are surprisingly tight, up to 0.0005in. (0.013mm). Macor® MGC can be machined to a surface finish of less than 20µin. (o.5µm) and polished to a smoothness of 0.5µin. (0.013µm). Configurations are limited only by available equipment and the experience of the machinist.

Sealing, joining and metalising

Macor® can also be joined or sealed-both to itself and to other materials-in a number of ways; metalised parts can be soldered together and brazing has proved to be effective method of joining the material to various metals: epoxy produces a strong joint, and sealing glass create a vacuum tight seal. Even a straight forward mechanical joint is possible. It can be thick film metalised using metal inks, or thin film metalised by sputtering. An example of vapour disposition metalising is shown on the examples page. Metal coatings available are Gold, Silver, Copper, Nickel, Platinum, Chrome and Tungsten. Other materials are available on request.


Ultra-high vacuum environments

Macor® is used as an insulator or coil support and for vacuum feed-troughs. In these applications the conductive materials are supported by the Macor® part and a compatible sealing glass is used to produce a vacuum-tight, hermetic seal.

Constant vacuum applications

Macor® parts are found in spacers, headers and windows for microwave tube devices and as sample holders in field ion microscopes.

Aerospace industry

Over 200 distinctly shaped Macor® parts can be found on America’s reusable Spacer Shuttle Orbiter. Retaining rings of Macor® are used at all hinge points, windows and doors.
Also, large pieces of Macor® glass ceramic are used in a NASA spaceborne gamma radiation detector. For this application frame corners are joined by a combination of machined (butt-lap) mechanical joints and a sealing glass.

Nuclear-related experiments

Since Macor® is not dimensionally affected by irradiation, small cubes of the material are machined to a tolerance of one micron and are used as a reference piece to measure dimensional change in other materials.

Welding nozzles

Welding equipment manufacturers are using Macor® as a nozzle on the tips of oxyacetylene torches. The material’s non-wetting characteristic means molten particles won’t adhere to and decrease the effectiveness of the nozzle.


Macor® is used as an electrode support and burner block in several industrial high heat, electrical cutting operations due to its low thermal conductivity and excellent electrical properties.

Medical Equipment

Producers of medical components are intrigued by Macor® MGC’s inertness, precise machinability and dimensional stability.


When you need the performance of a technical ceramic- (high use temperature, electrical resistivity, zero porosity) – and your application demands the ready fabrication of a complicated shape look at Macor®. It will lower costs and substantially reduce the time between design and actual use.

We have a wealth of further information regarding this very versatile material on our dedicated Macor Machinable Glass Ceramic website

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Lukely Works, Carisbrooke Road, Newport, Isle of Wight, United Kingdom, PO30 1DH
Tel: +44 (0)1983 528697 - Email:
Company Registration No.934853