World Library  
Flag as Inappropriate
Email this Article


Article Id: WHEBN0030855994
Reproduction Date:

Title: Macor  
Author: World Heritage Encyclopedia
Language: English
Subject: Inter Glass, CorningWare, Cranberry glass, Wood's glass, W. E. S. Turner
Collection: Glass Trademarks and Brands, Glass-Ceramics
Publisher: World Heritage Encyclopedia


Macor is the trademark for a machineable glass-ceramic developed and sold by Corning Inc. It is a white material that looks somewhat like porcelain. Macor is a good thermal insulator, and is stable up to temperatures of 1000 °C, with very little thermal expansion or outgassing. It can be machined into any shape using standard metalworking bits and tools.[1]


Macor is made up of fluorphlogopite mica in a borosilicate glass matrix. Its composition is roughly:


Macor has a density of 2.52 g/cm3, and a thermal conductivity of 1.46 W/(m·K). Its low-temperature (25 to 300 °C) thermal expansion is 9.3×10−6 m/(m·K). Its compressive strength is 50×103 lb/in2 (~350 MPa). Nominal engineering properties are comparable to borosilicate glass.[2]

Extremely machinable, Macor offers tight tolerances capabilities, allowing complicated shape design (optimal performances up to +/- 0.013 mm for dimensions, < 0.5 μm for finished surface and up to 0.013 μm for polished surface). Macor remains continuously stable at 800 °C, with a maximum peak at 1000 °C under no load, and unlike ductile materials, doesn’t creep or deform. Its coefficient of thermal expansion readily matches most metals and sealing glasses. As an electric insulator, particularly at high temperatures, it is excellent at high voltages and a broad spectrum of frequencies.

Macor comes in a standard size maxi slab (36x6cm approx.) Corning Macor Maxi-Slab.[3] Components, bars, rods and plates can be machined within the size of this slab (hand tools can be used).


Macor is used in the following applications: Constant and ultra-high vacuum environments • Laser technology • Semiconductor / Electronic • Aerospace / Space • Medical/ Laboratory equipment • Fixtures • Chemical • Automobile • Military • Nuclear


There are no major safety concerns or toxic effects associated with Macor. The dust created when machining it can be an irritant and inhalation should be avoided.[4]

Machining Guidelines

Key factors for successful machining are proper machining speeds and coolant. • Macor can be machined with high speed steel tools, but carbide tools are recommended for longer wear. • Best results achieved by using a watersoluble coolant(such as Cimstar 40 - Pink) especially formulated for cutting and grinding glass or ceramics. Note: No post firing is required after machining.


  1. ^ "Corning Specialty Materials". 
  2. ^ Compare Materials: Borosilicate Glass and Macor
  3. ^
  4. ^ "Macor Glass Ceramic". 

Corning Macor® Technical Brochure 2014'
Macor® Machining Guidelines 2014'
Corning Authorized Macor® Distributor

This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from World eBook Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.