ASTM B106-96

NOTICE: This standard has either been superseded and replaced by a new version or
withdrawn. Contact ASTM International (www.astm.org) for the latest information.
Designation: B 106 – 96 An American National Standard
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Test Methods for
1
Flexivity of Thermostat Metals
This standard is issued under the fixed designation B 106; 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 and T , it is necessary to measure the curvature 1/R and 1/R
2 1 2
at temperature T and T , respectively. To find the curvature at
1 2
1.1 These test methods cover the determination of flexivity
either temperature (Fig. 1 and Fig. 2), measure the distance D.
(a measure of thermal deflection rate or deflection temperature
The curvature is given by the following equation:
characteristics) of thermostat metals.
2 2
1.1.1 Test Method A—Tested in the form of flat strip 0.012
1/R 5 8D/~Q 1 4Dt 1 4D ! (2)
in. (0.30 mm) or over in thickness.
where:
1.1.2 Test Method B—Tested in the form of spiral coils less
R = radius of curvature of the longitudinal center line of
than 0.012 in. in thickness.
the specimen, in. (mm),
1.2 This standard does not purport to address all of the
t = thickness of test specimen, in. (mm),
safety concerns, if any, associated with its use. It is the
Q = distance between support points, in. (mm), and
responsibility of the user of this standard to establish appro-
D = for point support (simply supported
priate safety and health practices and determine the applica-
beam), = perpendicular distance between the
bility of regulatory limitations prior to use. It is the responsi-
longitudinal center lines of the lower surface of the
bility of the user to become familiar with all hazards, including
specimen midway between the point supports and the
those indentified in the appropriate material safety data sheet
straight line joining the support points, in. (mm).
for this material.
1.3 The values stated in inch-pound units are to be regarded 4. Significance and Use
as the standard. The values given in parentheses are provided
4.1 These test methods are used for determining response to
for information purposes only.
temperature change or flexivity of thermostat metal. The
flexivity is calculated from the temperatures, dimensions of
2. Referenced Documents
specimen, and the relative movement of the specimen. The
2.1 ASTM Standards:
simple beam method is the method for certification. Any use of
B 389 Test Method for Thermal Deflection Rate of Spiral
the spiral coil method (Method B) is to be mutually agreed
2
and Helical Coils of Thermostat Metal
upon between the user and supplier.
3. Terminology
TEST METHOD A—FLAT STRIPS
3.1 Definitions:
5. Apparatus
3.1.1 thermostat metal—a composite material in the form of
5.1 Specimen Carrier, provided with two conical supports
sheet or strip comprising two or more metallic layers of
for locating the specimen. The test length (that is, the distance
differing coefficients of thermal expansion, such that the radius
between the point of contact of the specimen with one support
of curvature of the composite changes with temperature
and the point of contact of the specimen with the other support)
change.
shall be known to within 60.005 in. (0.13 mm), and the line of
3.1.2 flexivity (F)—the change of curvature of the longitu-
plane passing through the points of contact shall be horizontal.
dinal center line of the specimen per unit temperature change
The specimen carrier and supports shall hold the specimen
for unit thickness, given by the following equation:
without constraint so that the curvature, due to its deflection,
~1/R ! 2 ~1/R !
2 1
F 5 t (1)
will follow a vertical plane passing through the line joining the
T 2 T
2 1
points of contact between specimen and supports.
To determine the flexivity between any two temperatures, T
1
5.2 Micrometer—traveling microscope, or equivalent
device, so connected to the specimen carrier that expansion
1 during heating of the carrier or connecting parts will not cause
These test methods are under the jurisdiction of ASTM Committee B-4 on
Metallic Materials for Thermostats and for Electrical Resistance Heating and appreciable displacement of the measuring device with respect
Contacts and are the direct responsibility of Subcommittee B04.03 on Thermostat
to the supports.
metals.
5.3 Bath—A stirred liquid bath or uniformly heated
Current edition approved Jan. 10, 1996. Published April 1996. Originally
enclosure in which the specimen carrier, together with
published as B 106 – 84. Last previous edition B 106 – 90.
2
Annual Book of ASTM Standards, Vol 03.04. adju
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