ASTM D2757-86(1999)

Standard Specification for Impervious Steatite Ceramics for Electrical and Electronic Applications (Withdrawn 2001)

SCOPE
1.1 This specification covers the requirements for impervious steatite ceramics having low electrical loss characteristics for use in electronic and electrical applications.  
1.2 Impervious steatite ceramics described in this specification shall be designated as Type I, Type II, Type III, and Type IV.  
1.3 The values stated in inch-pound units are to be regarded as the standard.

General Information

• Status: Withdrawn
• Publication Date: 09-Oct-1999
• Withdrawal Date: 09-May-2001
• ICS: 29.035.30 - Glass and ceramic insulating materials
• ICS: 81.060.20 - Ceramic products
• Technical Committee: C21 - Ceramic Whitewares and Related Products
• Drafting Committee: C21.03 - Methods for Whitewares and Environmental Concerns

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: D 2757 – 86 (Reapproved 1999)
Standard Specification for
Impervious Steatite Ceramics for Electrical and Electronic
Applications
This standard is issued under the fixed designation D 2757; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope trical requirements specified in Table 1.
1.1 This specification covers the requirements for impervi-
5. Dimensional Requirements
ous steatite ceramics having low electrical loss characteristics
5.1 The general dimensional tolerances listed below are to
for use in electronic and electrical applications.
be considered standard for most unground steatite ceramics,
1.2 Impervious steatite ceramics described in this specifica-
particularly those of simple geometry and good symmetry.
tion shall be designated as Type I, Type II, Type III, and Type
Tolerances differing from these should be specified on the part
IV.
drawing. Grinding and other finishing operations permit closer
1.3 The values stated in inch-pound units are to be regarded
dimensional tolerances.
as the standard.
5.1.1 Unglazed Surfaces—61 %, but not less than 60.005
2. Referenced Documents in. (0.127 mm).
5.1.2 Glazed Surfaces—62 % but not less than 60.012 in.
2.1 ASTM Standards:
(0.305 mm).
C 20 Test Methods for Apparent Porosity, Water Absorp-
5.1.3 Angular Dimensions—62°.
tion, Apparent Specific Gravity, and Bulk Density of
2 5.1.4 Parallelism will be considered satisfactory if the
Burned Refractory Brick and Shapes by Boiling Water
thickness measured at any point is within the dimensional
D 116 Test Methods for Testing Vitrified Ceramic Materials
3 tolerance.
for Electrical Applications
5.1.5 Ellipticity for deviation from a true circle, will be
D 150 Test Methods for A-C Loss Characteristics and
considered satisfactory with a value of 1.02 when the wall
Permittivity (Dielectric Constant) of Solid Electrical Insu-
thickness is 12 %, or more, of the outside diameter. A maxi-
lation
mum value of 1.03 will be permitted for a wall thickness of
D 2520 Test Methods for Complex Permittivity (Dielectric
10 % of the outside diameter (see Annex A1).
Constant) of Solid Electrical Insulating Materials at Mi-
5.1.6 Concentricity, shall be expressed as a deviation of
crowave Frequencies and Temperatures to 1650°C
centers of a cylinder. Normally a total dial indicator reading of
E 18 Test Methods for Rockwell Hardness and Rockwell
1 % of the outside diameter or 0.010 in. (0.254 mm), which-
Superficial Hardness of Metallic Materials
ever is larger, will be permitted where all diameters are either
3. Description of Term Specific to This Standard
all ground or all unground (see Annex A1).
5.1.7 Camber, shall be expressed as the ratio between arc
3.1 impervious steatite ceramics—steatite ceramics show-
and the maximum length of the part. A maximum camber of
ing no perceptible dye penetration when tested in accordance
0.006 in./in. (0.152 mm) of length is permitted unless other-
with Method C of Test Methods D 116.
wise specified (see Annex A1).
4. Electrical Requirements
6. Visual Requirements
4.1 Impervious steatite ceramics shall conform to the elec-
6.1 Parts shall be uniform in color and texture. Visible
defects, such as pits, chips, cracks, and blisters, shall not be
This specification is under the jurisdiction of ASTM Committee C-21 on
permitted to the extent that the life and usefulness of the
Ceramic Whitewares and Related Products and is the direct responsibility of C21.03
ceramic is impaired. Normal quality will allow defects up to
on Test Methods for Whiteware Properties.
0.031 in. (0.8 mm) unless otherwise specified.
Current edition approved Oct. 31, 1986. Published December 1986. Originally
e1
published as D 2757 – 68 T. Last previous edition D 2757– 86 (1994) .
Annual Book of ASTM Standards, Vol 15.01. 7. Handling
Annual Book of ASTM Standards, Vol 10.01.
4 7.1 All parts shall be handled, inspected, and packaged in
Annual Book of ASTM Standards, Vol 10.02.
such a manner as to avoid contamination and to prevent contact
Annual Book of ASTM Standards, Vol 03.01.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
---------------------- Page
...