ASTM D4508-04

Standard Test Method for Chip Impact Strength of Plastics

SCOPE
1.1 The purpose of this test method is to provide an impact test that can be performed on small specimens of plastics of different thicknesses. This test method is especially suited for observing the effects of microcracks caused by weathering, or by exposure to solvents or other hostile environments, on the surface of plastic materials. It is not meant to be used as a replacement for any existing impact test, but can be used to measure impact on coupons machined from finished parts that cannot be tested by the drop-weight, Izod, or Charpy method because of shape or thickness limitations.
1.2 The chip-impact test is run on small, flat, unnotched specimens using a standard pendulum-impact device. The test places the impacted surface in tension and, for notch-sensitive materials, is extremely sensitive to the presence of surface microcracks. Thus, for plastics that develop surface cracks when exposed outdoors, the chip-impact test is a severe test of the weathered impact strength.
1.3 Round-robin testing has indicated that materials that break at total energy values of less than 0.17 joules [1.5 in.-lbf] have within-laboratory coefficients of variation of approximately 30 %. Therefore, such values are considered out of the normal testing range for this test.
1.4 The values stated in SI units are to be regarded as the standard. The values given in brackets are for information only.
1.5 There is no ISO equivalent to this test method.
1.6 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

• Status: Historical
• Publication Date: 31-Jan-2004
• ICS: 83.080.01 - Plastics in general
• Technical Committee: D20 - Plastics
• Drafting Committee: D20.10 - Mechanical Properties

Relations

• Replaces: ASTM D4508-98 - Standard Test Method for Chip Impact Strength of Plastics
• Effective Date: 01-Feb-2004
• Replaced By: ASTM D4508-04a - Standard Test Method for Chip Impact Strength of Plastics
• Effective Date: 01-Nov-2004
• Referred By: ASTM G178-16(2023) - Standard Practice for Determining the Activation Spectrum of a Material (Wavelength Sensitivity to an Exposure Source) Using the Sharp Cut-On Filter or Spectrographic Technique
• Effective Date: 01-Feb-2004

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Please contact ASTM International (www.astm.org) for the latest information.
Designation: D 4508 – 04
Standard Test Method for
1
Chip Impact Strength of Plastics
This standard is issued under the fixed designation D 4508; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (ϵ) indicates an editorial change since the last revision or reapproval.
1. Scope* D256 Test Method for Determining the Pendulum Impact
Resistance of Notched Specimens of Plastics
1.1 The purpose of this test method is to provide an impact
D618 Practice for Conditioning Plastics for Testing
test that can be performed on small specimens of plastics of
D883 Terminology Relating to Plastics
different thicknesses. This test method is especially suited for
D1600 Terminology for Abbreviated Terms Relating to
observing the effects of microcracks caused by weathering, or
Plastics
by exposure to solvents or other hostile environments, on the
D4000 Classification System for Specifying Plastic Mate-
surface of plastic materials. It is not meant to be used as a
rials
replacement for any existing impact test, but can be used to
D4066 Classification System for Nylon Injection and Ex-
measure impact on coupons machined from finished parts that
trusion Materials (PA)
cannot be tested by the drop-weight, Izod, or Charpy method
D5947 Test Methods for Physical Dimensions of Solid
because of shape or thickness limitations.
Plastics Specimens
1.2 The chip-impact test is run on small, flat, unnotched
E691 Practice for Conducting an Interlaboratory Study to
specimens using a standard pendulum-impact device. The test
Determine the Precision of a Test Method
places the impacted surface in tension and, for notch-sensitive
IEEE/ASTM SI-10 American National Standard for Use of
materials, is extremely sensitive to the presence of surface
the International System of Units (SI): The Modern Metric
microcracks. Thus, for plastics that develop surface cracks
System
when exposed outdoors, the chip-impact test is a severe test of
the weathered impact strength.
3. Terminology
1.3 Round-robin testing has indicated that materials that
3.1 Definitions—For definitions of plastic terms see Termi-
breakattotalenergyvaluesoflessthan0.17joules[1.5in.-lbf]
nology D883D883 and for abbreviations see Terminology
have within-laboratory coefficients of variation of approxi-
D1600D1600. There are no terms in this test method that
mately 30%. Therefore, such values are considered out of the
require new or other-than-dictionary definitions.
normal testing range for this test.
1.4 The values stated in SI units are to be regarded as the
4. Significance and Use
standard.Thevaluesgiveninbracketsareforinformationonly.
4.1 The chip-impact test is a variation of the Izod impact
1.5 There is no ISO equivalent to this test method.
test described in Test Methods D256.
1.6 This standard does not purport to address all of the
4.2 The specimen geometry has been chosen to fit three
safety concerns, if any, associated with its use. It is the
basic criteria as follows:
responsibility of the user of this standard to establish appro-
4.2.1 The specimen is relatively thin and is struck on the
priate safety and health practices and determine the applica-
broad surface so that the test result is sensitive to the condition
bility of regulatory limitations prior to use.
of the surface,
4.2.2 The specimen is relatively small for efficient utiliza-
2. Referenced Documents
2
tion of space in accelerated testing media or devices and to
2.1 ASTM Standards:
minimize amounts of material needed for testing, and
4.2.3 The specimen can be tested using a standard Izod
pendulum tester.
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ThistestmethodisunderthejurisdictionofASTMCommitteeD20onPlastics
4.3 It has been found that a 12.7-mm [0.500-in.] wide strip
and is the direct responsibility of Subcommittee D20.10 on Mechanical Properties.
with a thickness in the range from 1.02 to 3.18 mm [0.040 to
Current edition approved February 1, 2004. Published March 2004. Originally
approved in 1985. Last previous edition approved in 1998 as D4508-98.
0.125 in.] meets the above criteria. Much experimental work
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
on 1.78-mm [0.070-in.] strips has demonstrated the utility of
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
the chip-impact test to track weather aging of a variety of
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. materials.
*A Summary of Changes section appears at the end of this standard.
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