Silicates

Silicate ceramics were the first technical ceramics developed to support early electrical technologies, including Magnesium Aluminosilicates (Steatite and Cordierite) and Mullite. At STC we import Grade A Lava (Hydrous Aluminum Silicate), a naturally occurring silicate material that is shares many of the performance advantages of the engineered silicates.

In general, silicates are valuable for their good thermal insulation, resistance to thermal shock and high temperature performance. In recent years, these materials are seeing new applications based on their low RF loss factors and low thermal expansion.

These materials are a low-cost alternative to high purity ceramics based on their natural ingredients.

Property Charts & Safety Data Sheets

Master Ceramics Property Chart: Full Color

Safety Data Sheets: Safety Data Sheet Library

Prime Features

Lower Cost: Good Electrical Insulation

Low Coefficient Of Thermal Expansion: High Thermal Shock Resistance

Low Weight: Good Thermal Insulation

Typical Applications

Structural Ceramic Parts: Aerospace

Medical: Bearings

Analytical Instrumentation

Cordierite

Its good thermal shock properties lend this material to be used in refractory applications. Its low thermal expansion and thermal conductivity make it a good choice for fixtures and other applications. Cordierite is the lowest thermal expansion ceramic produced at STC.

Property Charts & Safety Data Sheets

Master Ceramics Property Chart: Full Color

Safety Data Sheets: Safety Data Sheet Library

Lava (Grade "A")

Grade A Lava is a machinable ceramic that exhibits good electrical and heat resistance. Excellent thermal shock properties allow it to be used in applications where long term thermal cycling is a consideration. Low thermal conductivity is also a highlight of this material.

Lava is a natural, mined stone known as hydrous aluminum silicate. This machinable ceramic material has many applications in both the unfired and fully fired state. We offer unfired feedstock in block, rod, plate or bar form and also provide fired, finished components manufactured to your technical specifications.

Unfired lava is a free machining material, easily worked with normal tooling and methods. It can be milled, turned, drilled, tapped and threaded. Commonly used as a prototyping material and for fixturing used in high temperature applications.

Unfired machined parts are hardened by kiln firing and once fired they are only workable by diamond grinding. This material has a predictable expansion of about 2% which must be taken into consideration while machining if the part is to be fired. Lava is capable of maintaining very close tolerances from the unfired to fired state, often eliminating the need for additional after firing grinding.

Fully fired lava becomes very hard and has superb thermal shock and excellent electrical properties. It is well suited to applications demanding repeated thermal cycling.

Lava is a natural material with a range of color and texture. Texture ranges from smooth/glossy to rough/dull. Color varies from light tan to dark black. Texture and color can be uniform or mottled in the same part or batch of parts. This variation is to be expected as a normal characteristic of the material.

Property Charts & Safety Data Sheets

Master Ceramics Property Chart: Full Color

Safety Data Sheets: Safety Data Sheet Library

Mullite

Mullite is an excellent material due to its very high temperature stability, decent strength and high creep resistance. It is commonly used in heater exchange parts and electrical insulators.

Property Charts & Safety Data Sheets

Master Ceramics Property Chart: Full Color

Safety Data Sheets: Safety Data Sheet Library

Steatite

Steatite is a low cost material with high electrical resistance at high temperatures, good mechanical strength and a very low dielectric loss factor. Such properties make it ideal for high frequency, low loss, and high voltage insulation. Moreover, steatite is an excellent material for electrical engineering as it can be readily shape sintered into a wide variety of forms such as washers, bushings, resistor forms, spaces and beads.

Steatite has been used for many years in large-scale industrial systems, household electronic appliances, aerospace and automotive applications, and specialized eletro-technical instruments such as cathode-ray tubes.

Property Charts & Safety Data Sheets

Master Ceramics Property Chart: Full Color

Safety Data Sheets: Safety Data Sheet Library

Prime Features

Low Cost Material: High Electrical Resistance At High Temperatures

Good Mechanical Strength: Very Low Dielectric Loss Factor

Typical Applications

Excellent Material For Electrical Engineering: Large-Scale Industrial Systems

Household Electronic Appliances: Aerospace And Automotive Engineering

Specialized Eletro-Technical Instruments (E.G. Cathode-Ray Tubes)

Certifications

Click below to view our Quality Certifications, Registrations and Compliance

AS9100 & ISO 9001

STC RoHS Compliance Statement

Superior Technical Ceramics (STC) makes no stand-alone electronic or electrical products but is proud to be a subcontractor of ceramics used in electronic and electrical products. STC has been asked by numerous customers to confirm that our ceramics are RoHS Compliant.

After a complete bi-annual review of the materials used in our parts and the manufacturing process, we can advise you, our customers, that STC is RoHS & RoHS 3 compliant.

March 4, 2025

RoHS stands for Restriction of Hazardous Substances and impacts the entire electronics industry and many electrical products as well. The original RoHS, also known as Directive 2002/95/EC, originated in the European Union in 2002 and restricts the use of six hazardous materials found in electrical and electronic products. All applicable products in the EU market from July 1, 2006, must pass RoHS compliance.

Directive 2011/65/EU was published in 2011 by the EU, which is known as RoHS-Recast or RoHS 2. RoHS 2 includes a CE-marking directive, with RoHS compliance now being required for CE marking of products. RoHS 2 also added Categories 8 and 9 and has additional compliance recordkeeping requirements.

Directive 2015/863 is known as RoHS 3. RoHS 3 adds four additional restricted substances (phthalates) to the list of six.

EU RoHS specifies maximum levels for the following 10 restricted substances. The first six applied to the original RoHS while the last four were added under RoHS 3, which took effect July 22, 2019.

Cadmium (Cd): < 100 ppm
Lead (Pb): < 1000 ppm
Mercury (Hg): < 1000 ppm
Hexavalent Chromium: (Cr VI) < 1000 ppm
Polybrominated Biphenyls (PBB): < 1000 ppm
Polybrominated Diphenyl Ethers (PBDE): < 1000 ppm
Bis(2-Ethylhexyl) phthalate (DEHP): < 1000 ppm
Benzyl butyl phthalate (BBP): < 1000 ppm
Dibutyl phthalate (DBP): < 1000 ppm
Diisobutyl phthalate (DIBP): < 1000 ppm

RoHS 3 (EU Directive 2015/863) adds Category 11 (catch-all) products and adds four new restricted substances – all phthalates. The four phthalates are mainly used as insulation plasticizers and are on the REACH list of SVHC (Substances of Very High Concern). The expanded list for RoHS 3 is thus as follows:

Cadmium (0.01 %)
Lead (0.1 %)
Mercury (0.1 %)
Hexavalent chromium (0.1 %)
Polybrominated biphenyls (PBB) (0.1 %)
Polybrominated diphenyl ethers (PBDE) (0.1 %)
Bis(2-ethylhexyl) phthalate (DEHP) (0.1 %)
Butyl benzyl phthalate (BBP) (0.1 %)
Dibutyl phthalate (DBP) (0.1 %)
Diisobutyl phthalate (DIBP) (0.1 %)

Download a PDF of our registration letter here.

Silicates

Property Charts & Safety Data Sheets

Prime Features

Typical Applications

Cordierite

Property Charts & Safety Data Sheets

Lava (Grade "A")

Property Charts & Safety Data Sheets

Mullite

Property Charts & Safety Data Sheets

Steatite

Property Charts & Safety Data Sheets

Prime Features

Typical Applications

Certifications

ITAR Registered

View our ITAR Registration Letter

ITAR Registered

View our ITAR Registration Letter