ASTM C368-88(2011)
(Test Method)Standard Test Method for Impact Resistance of Ceramic Tableware
Standard Test Method for Impact Resistance of Ceramic Tableware
SIGNIFICANCE AND USE
The purpose of this test method is to predict product resistance to impact breakage in service.
SCOPE
1.1 This test method covers the following tests:
1.1.1 Impact tests at the center of both flatware and hollow ware and at the rim of hollow ware, and
1.1.2 Chipping tests at the rim of flatware. Specimens may be either glazed or unglazed. Note 1The impact test at the center of the specimen is used to determine: (1) the magnitude of a blow that will produce initial fracture, and (2) the amount of energy necessary to produce complete failure. In the first case, the initial fracture shows on the side of the piece opposite from that being struck and appears to be a function of the square of the thickness and of the inherent brittleness of the body or body-glaze combination; it is relatively independent of the size or design of the specimen. The second factor is more dependent upon design and often is subject to wide variation within a given group of pieces.
Note 2
The impact test at the rim of hollow ware is similar to a chipping test, and the type of failure that is obtained is useful in evaluating the effect of the shape of the object.
Note 3
In addition to the inherent strength of the body, chipping test results are greatly affected by contour of rim and to a lesser extent by thickness of rim, inclination of leaf, and fit of glaze.
1.2 The values stated in inch-pound units are to be regarded as the standard. The SI (metric) units given in parentheses are for information purposes only.
This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
General Information
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Standards Content (Sample)
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Designation: C368 − 88(Reapproved 2011)
Standard Test Method for
Impact Resistance of Ceramic Tableware
This standard is issued under the fixed designation C368; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope 4. Apparatus
1.1 This test method covers the following tests: 4.1 Impact Tester, Pendulum Type—The impact test appara-
1.1.1 Impact tests at the center of both flatware and hollow tus (Figs. 1 and 2) shall consist of a device having the
ware and at the rim of hollow ware, and following essential features:
1.1.2 Chipping tests at the rim of flatware. Specimens may 4.1.1 Asteel tup of specified size and of hardness Rockwell
be either glazed or unglazed. C55,
4.1.2 Support of a tup by a V-suspension,
NOTE 1—The impact test at the center of the specimen is used to
4.1.3 Provision for a means of release from fixed heights so
determine: (1) the magnitude of a blow that will produce initial fracture,
astogivereproducibleresults,independentoftheoperator,and
and (2) the amount of energy necessary to produce complete failure. In the
first case, the initial fracture shows on the side of the piece opposite from
4.1.4 Provision for holding the test specimen in place by
that being struck and appears to be a function of the square of the
spring clamps against rigid metal supports.
thickness and of the inherent brittleness of the body or body-glaze
4.2 Micrometer—For measuring thickness of test
combination; it is relatively independent of the size or design of the
specimen. The second factor is more dependent upon design and often is
specimens, a micrometer caliper that can be read to 0.001 in.
subject to wide variation within a given group of pieces.
(0.03 mm) shall be used.
NOTE 2—The impact test at the rim of hollow ware is similar to a
chipping test, and the type of failure that is obtained is useful in evaluating
5. Test Specimens
the effect of the shape of the object.
NOTE 3—In addition to the inherent strength of the body, chipping test 5.1 Specimens shall be selected so as to be representative of
results are greatly affected by contour of rim and to a lesser extent by
thelotbeingsampled.Ingeneral,impacttestsshallbebasedon
thickness of rim, inclination of leaf, and fit of glaze.
a minimum of ten specimens and chipping tests on at least five
1.2 The values stated in inch-pound units are to be regarded
specimens. Specimens shall be inspected for soundness and
as the standard. The SI (metric) units given in parentheses are
obvious physical defects before testing.
for information purposes only.
6. Procedure for Impact Testing of Flatware
1.3 This standard does not purport to address all of the
6.1 Mount the cylindrical tube shown in Fig. 2 (Note 4)on
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- the backstop, C , Fig. 1, and set at a height such that the three
ball bearings mounted in the end of the cylindrical tube are in
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use. contact and symmetrical with the central portion of the
specimen, which shall be stood on edge on the base plate. The
2. Referenced Documents
specimen may be tested with either the face or the back toward
the hammer; in general, a lower failure value is obtained when
2.1 ASTM Adjuncts:
the face is struck. Adjust the backstop so that the spherical
ADJC0368 Machine for Testing Chinaware
surface of the tup, D, just touches the surface of the specimen
when the tup is hanging free (vertically). Tighten the two wing
3. Significance and Use
nuts at the base of the backstop.
3.1 The purpose of this test method is to predict product
resistance to impact breakage in service. NOTE 4—In this portion of the test, the cylindrical tube replaces the
angle clamp, E, shown in position on the backstop, C,in Fig. 1.
6.2 Adjust the positioning arms,F, held in retracted position
This test method is under the jurisdiction ofASTM Committee C21 on Ceramic
by means of their cotter keys so that the forward edges of the
Whitewares and Related Products and is the direct responsibility of Subcommittee
sleeve and of the clamp coincide. Adjust the clamps on the
C21.03 on Methods for Whitewares and Environmental Concerns.
Current edition approved March 1, 2011. Published March 2011. Originally
vertical posts to grip the specimen at the same height that the
approvedin1955.Lastpreviouseditionapprovedin2006asC368–88(2006).DOI:
pendulum will strike it; that is, halfway up.Adjust the arms so
10.1520/C0368-88R11.
that the rubber-covered surface at right angles to its rod will
Detailed working drawings of the apparatus are available from ASTM
Headquarters. Request Adjunct No. ADJC0368. contact the rim of the sample; remove the cotter keys to permit
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C368 − 88 (2011)
FIG. 1 Impact Test Apparatus
position by means of the handwheels, A, so that the tup strikes
the center of the specimen.
6.3 With the preliminary adjustments completed, subject the
specimen to a schedule of impacts starting at 0.02 ft·lbf (0.027
J) and increasing in increments of 0.01 ft·lbf (0.014 J) until
initial fracture, and in increments of 0.02 ft·lbf thereafter to
FIG. 2 Tube to Support Flatware Specimen
failure.
NOTE 5—The tests may be performed rapidly by grasping the portion of
the releasing device that lies below the dial segment from beneath with the
the positioning arms to hold the specimen against the cylindri-
tip of the middle finger of the right hand and moving it back to the correct
cal tube. Adjust the pendulum support bar, B, and lock it in notch for the next blow immediately after the tup has been released. Catch
...
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