ASTM D350-21

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D350 − 13 D350 − 21
Standard Test Methods for
Flexible Treated Sleeving Used for Electrical Insulation
This standard is issued under the fixed designation D350; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope*Scope
1.1 These test methods cover procedures for testing electrical insulating sleeving comprising a flexible tubular product made from
a woven textile fibre base, such as cotton, rayon, nylon, or glass, thereafter impregnated, or coated, or impregnated and coated,
with a suitable dielectric material.
1.2 The procedures appear in the following sections:
Procedures Section(s)
Selection of Test Material 5
Conditioning 6
Dimensions 7 to 11
Dielectric Breakdown Voltage 12 to 17
Brittleness Temperature 18 to 21
Flammability (See Test Methods D8355) 22 to 23
Dielectric Breakdown Voltage After Short-Time Aging 24 to 28
Oil Resistance 29 to 32
Thermal Endurance 33 to 39
Compatibility of Sleeving with Magnet Wire Insulation 40 to 54
Solvent Resistance 55 to 60
Hydrolytic Stability 61 to 67
Effect of Push-Back After Heat Aging 68 to 73
Procedures Sections
Brittleness Temperature 18 to 21
Compatibility of Sleeving with Magnet Wire Insulation 45 to 59
Conditioning 6
Dielectric Breakdown Voltage 12 to 17
Dielectric Breakdown Voltage After Short-Time Aging 29 to 33
Dimensions 7 to 11
Effect of Push-Back After Heat Aging 73 to 78
Flammability 22 to 28
Hydrolytic Stability 66 to 72
Oil Resistance 34 to 37
Selection of Test Material 5
Solvent Resistance 60 to 65
Thermal Endurance 38 to 44
1.3 The values stated in inch-pound units, except for °C, are to be regarded as the standard. The values in parentheses are
mathematical conversions to SI units that are provided for information only and are not considered standard.
These test methods are under the jurisdiction of ASTM Committee D09 on Electrical and Electronic Insulating Materials and are the direct responsibility of Subcommittee
D09.07 on Flexible and Rigid Electrical Insulating Materials.
Current edition approved Nov. 1, 2013Jan. 1, 2021. Published December 2013February 2021. Originally approved in 1932. Last previous edition approved in 20092013
as D350 – 09.D350 – 13. DOI: 10.1520/D0350-13.10.1520/D0350-21.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D350 − 21
1.4 This is a fire-test-response standard. See SectionsTest 22 throughMethods D835528, which are the contains procedures for
flammability tests.
1.5 This standard measures and describes the response of materials, products, or assemblies to heat and flame under controlled
conditions, but does not by itself incorporate all factors required for fire hazard or fire risk assessment of the materials, products
or assemblies under actual fire conditions.
1.5 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use. For specific hazard statements, see 45.240.2 and 63.1.158.1.1.
NOTE 1—This standard resembles IEC 60684-2, Specification for Flexible Insulating Sleeving—Part 2 Methods of Test, in a number of ways, but is not
consistently similar throughout. The data obtained using either standard are not necessarily technically equivalent.
1.7 Fire testing is inherently hazardous. Adequate safeguards for personnel and property shall be employed in conducting these
tests.
1.6 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
D149 Test Method for Dielectric Breakdown Voltage and Dielectric Strength of Solid Electrical Insulating Materials at
Commercial Power Frequencies
D374 Test Methods for Thickness of Solid Electrical Insulation (Metric) D0374_D0374M
D471 Test Method for Rubber Property—Effect of Liquids
D746 Test Method for Brittleness Temperature of Plastics and Elastomers by Impact
D876 Test Methods for Nonrigid Vinyl Chloride Polymer Tubing Used for Electrical Insulation
D1711 Terminology Relating to Electrical Insulation
D2307 Test Method for Thermal Endurance of Film-Insulated Round Magnet Wire
D3487 Specification for Mineral Insulating Oil Used in Electrical Apparatus
D3636 Practice for Sampling and Judging Quality of Solid Electrical Insulating Materials
D5423 Specification for Forced-Convection Laboratory Ovens for Evaluation of Electrical Insulation
D6054 Practice for Conditioning Electrical Insulating Materials for Testing (Withdrawn 2012)
D8355 Test Methods for Flammability of Electrical Insulating Materials Used for Sleeving or Tubing
E145 Specification for Gravity-Convection and Forced-Ventilation Ovens
E176 Terminology of Fire Standards
2.2 IEEE Standard:
IEEE 101 Guide for the Statistical Analysis of Thermal Life Test Data
2.3 IEC Standard:
IEC 60684-2 Specification for Flexible Insulating Sleeving—Part 2 Methods of Test
2.4 ISO Standard:
ISO 13943 Fire Safety—Vocabulary
3. Terminology
3.1 Definitions:
3.1.1 Use Terminology E176 and ISO 13943 for definitions of terms used in this test method and associated with fire issues. Where
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
The last approved version of this historical standard is referenced on www.astm.org.
Available from Institute of Electrical and Electronics Engineers, Inc. (IEEE), 445 Hoes Ln., P.O. Box 1331, Piscataway, NJ 08854-1331,08854-4141, http://www.ieee.org.
Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.
Available from International Organization for Standardization (ISO), ISO Central Secretariat, Chemin de Blandonnet 8, CP 401, 1214 Vernier, Geneva, Switzerland,
https://www.iso.org.
D350 − 21
differences exist in definitions, those contained in Terminology E176 shall be used. Use Terminology D1711 for definitions of
terms used in this test method and associated with electrical insulation materials.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 size, n—a numerical designation which indicates that the inside diameter of the sleeving lies within the limits prescribed in
Table 1.
3.2.2 wall thickness, n—one half the difference between the outside diameter of the sleeving mounted on a loosely fitting
gagegauge rod and the diameter of the gagegauge rod when measured in accordance with 9.2.
4. Apparatus and Materials
4.1 Ovens used in these test methods shall meet the requirements of Specification D5423.
5. Selection of Test Material
5.1 In the case of sleeving on spools or in coils, not less than three turns of the product shall be removed before the selection of
material from which test specimens are to be prepared.
5.2 In the case of sleeving offered in cut lengths, test specimens shall not be prepared from material closer than 1 in. (25 mm)
from each end.
5.3 Specimens for test shall not show obvious defects unless the purpose of the test is to determine the effect of such defects.
5.4 Specimens shall be prepared from samples selected in accordance with Practice D3636. The sampling plan and acceptance
quality level shall be as agreed upon between the user and the producer.
TABLE 1 ASTM Standard Sizes for Flexible Sleeving
Inside Diameter, in. (mm)
Size
Max Min
1 in. 1.036 (26.3) 1.000 (25.4)
⁄8 in. 0.911 (23.1) 0.875 (22.2)
⁄4 in. 0.786 (20.0) 0.750 (19.1)
⁄8 in. 0.655 (16.6) 0.625 (15.9)
⁄2 in. 0.524 (13.3) 0.500 (12.7)
⁄16 in. 0.462 (11.7) 0.438 (11.1)
⁄8 in. 0.399 (10.1) 0.375 (9.5)
No. 0 0.347 (8.8) 0.325 (8.3)
No. 1 0.311 (7.9) 0.289 (7.3)
No. 2 0.278 (7.1) 0.258 (6.6)
No. 3 0.249 (6.3) 0.229 (5.8)
No. 4 0.224 (5.7) 0.204 (5.2)
No. 5 0.198 (5.0) 0.182 (4.6)
No. 6 0.178 (4.5) 0.162 (4.1)
No. 7 0.158 (4.0) 0.144 (3.7)
No. 8 0.141 (3.6) 0.129 (3.3)
No. 9 0.124 (3.1) 0.114 (2.9)
No. 10 0.112 (2.8) 0.102 (2.6)
No. 11 0.101 (2.6) 0.091 (2.31)
No. 12 0.091 (2.31) 0.081 (2.06)
No. 13 0.082 (2.08) 0.072 (1.83)
No. 14 0.074 (1.88) 0.064 (1.63)
No. 15 0.067 (1.70) 0.057 (1.45)
No. 16 0.061 (1.55) 0.051 (1.30)
No. 17 0.054 (1.37) 0.045 (1.14)
No. 18 0.049 (1.24) 0.040 (1.02)
No. 20 0.039 (0.99) 0.032 (0.81)
No. 22 0.032 (0.81) 0.025 (0.64)
No. 24 0.027 (0.69) 0.020 (0.51)
D350 − 21
6. Conditioning
6.1 Unless otherwise specified, a standard laboratory atmosphere of 50 6 5 % relative humidity and 23 6 2 °C (73.4 6 3.6 °F)
shall be used in conducting all tests and for conditioning specimens for a period of at least 18 h prior to testing.
6.2 In the case of dielectric breakdown voltage tests after humidity conditioning, specimens shall be conditioned for 96 h in an
atmosphere of 93 6 3 % relative humidity and 23 6 2 °C (73.4 6 3.6 °F) before testing. If a conditioning cabinet is used,
specimens shall be tested for dielectric breakdown voltage within 1 min after removal from the cabinet.
6.3 For details regarding conditioning, refer to Practice D6054.
DIMENSIONS
7. Apparatus
7.1 GageGauge Rods—Standard gagegauge rods shall be made of steel and shall have smooth surfaces and rounded edges. One
rod is required for each of the maximum and minimum diameters shown in Table 1 for each size. Each rod shall be within 60.005
in. (66.012 mm) of the values shown in Table 1.
8. Test Specimens
8.1 Five test specimens of at least 7 in. (180 mm) in length shall be cut from material obtained in accordance with Section 5.
9. Procedure
9.1 Inside Diameter—Pass the minimum gagegauge rod for the size sleeving under test into the specimen for a distance of 5 in.
(127 mm) without expanding the wall of the sleeving. If the rod has a snug fit, then consider the specimen as having an inside
diameter equal to the diameter of the rod. If the minimum gagegauge rod fits loosely, insert the maximum gagegauge rod into the
specimen. If the maximum gagegauge rod passes freely into the specimen for a distance of 5 in. with a snug fit, or if it expands
the wall of the specimen, then consider the sleeving to be of that size which falls within the limits of the maximum and minimum
inside diameters as represented by the gagegauge rods.
9.2 Wall Thickness—Insert in the specimen the largest standard gagegauge rod that will pass freely into the sleeving. Apply a
micrometer over the specimen and make thickness measurements as specified in Method C of Test Methods D374 except that the
force on the pressor foot shall be 3 oz (85 g). Obtain the average of five thickness readings taking the micrometer readings at
approximately 90° intervals about the circumference of the specimen and spaced lineally approximately 0.25 in. (6 mm). Methods
A and B of Test Methods D374 can be used as alternative methods where agreed upon between the manufacturer and purchaser.
Compute wall thickness as half the distance between the outside diameter of the mounted sleeving and the diameter of the
gagegauge rod.
10. Report
10.1 Report the following information:
10.1.1 Identification of the sleeving,
10.1.2 Method of measurement if other than Method C,
10.1.3 Size of sleeving, and
10.1.4 Wall thickness.
11. Precision and Bias
11.1 Precision—The overall estimates of the precision within laboratories (Sr) and the precision between laboratories (SR) for
j j
D350 − 21
TABLE 2 Estimated Precision of Wall Thickness Measurement
Nominal Value, (Sr) , (SR) ,
j j
Sleeving Type
in. (mm) in. (mm) in. (mm)
Acrylic 0.0213 (0.54) 0.0007 (0.018) 0.0017 (0.043)
PVC 0.0237 (0.60) 0.0007 (0.018) 0.0021 (0.053)
Silicone Rubber 0.0331 (0.84) 0.0012 (0.030) 0.0019 (0.048)
the determination of wall thickness are given in Table 2 for three selected materials. These estimates are based on a round robin
of the three materials with six laboratories participating.
11.2 Bias—This test method has no bias because the value for wall thickness is determined solely in terms of this test method
itself.
DIELECTRIC BREAKDOWN VOLTAGE
12. Significance and Use
12.1 The dielectric breakdown voltage of the sleeving is of importance as a measure of its ability to withstand electrical stress
without failure. This value does not correspond to the dielectric breakdown voltage expected in service, but is of value in
comparing different materials or different lots, in controlling manufacturing processes or, when coupled with experience, for a
limited degree of design work. The comparison of dielectric breakdown voltage of the same sleeving before and after
environmental conditioning (moisture, heat, and the like) gives a measure of its ability to resist these effects. For a more detailed
discussion, refer to Test Method D149.
13. Apparatus
13.1 Inner Electrode—A straight suitable metallic conductor which fits snugly into the sleeving, without stretching the wall, in
such a manner that one end of the wire is exposed and can be used to support the specimen.
13.1.1 For specimens having an inside diameter greater than about size 8, the use of stranded conductors or of a bundle of wires
of smaller size, is recommended, instead of using a solid conductor.
13.2 Outer Electrode—Strips of soft metal foil 1-in. (25-mm) (25 mm) wide and not more than 0.001 in. (0.03 mm) in thickness.
14. Procedure A—Straight Specimens
14.1 Test Specimens—Ten specimens 7 in. (180 mm) long shall be prepared for each conditioning test (see Section 6) from
material selected in accordance with Section 5.
14.2 Procedure:
14.2.1 After conditioning in accordance with 6.1, determine the dielectric breakdown voltage in accordance with Test Method
D149 except as specified in 14.2.2 and 14.2.3.
14.2.2 Mount a sleeving specimen on the inner electrode. Wrap the outer electrode tightly on the outside of the sleeving at a
distance of not less than 1 in. (25 mm) from the ends of the specimens. Snugly wrap the foil over the sleeving. Wind two more
turns of foil over the first turn, leaving a free end of about 0.5 in. (13 mm) to which an electrical contact can be made.
14.2.3 Determine the breakdown voltage, in accordance with Test Method D149 by the short time method, increasing the voltage
from zero at a rate of 0.5 kV/s. Calculate the average breakdown voltage for the ten tests.
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Service at service@astm.org.
D350 − 21
15. Procedure B—90° Bent Specimens
15.1 Test Specimens—Ten specimens 4 in. (100 mm) long shall be prepared for each conditioning test (see Section 6) from
material selected in accordance with Section 5.
15.2 Procedure:
15.2.1 Mount a sleeving specimen on the inner electrode.
15.2.2 Bend the specimen through an angle of 90 6 2° over a smooth mandrel having a diameter of ten times the nominal inside
diameter of the specimen. Arrange the bend so that it is centrally located on the specimen.
15.2.3 Condition the samples as specified in 6.1.
15.2.4 Determine the dielectric breakdown voltage of the bent specimen using the following procedure:
15.2.4.1 Carefully wrap a strip of metal foil as in 14.2.2 snugly over the specimens at the bend. In accordance with Test Method
D149 apply a voltage starting at zero and increasing at a constant rate of 0.5 kV/s until breakdown. Calculate the average
breakdown voltage of the ten specimens.
15.2.4.2 Apply the foil electrode after exposure to conditioning.
16. Report
16.1 Report the following information:
16.1.1 Identification of the sleeving,
16.1.2 Conditioning before test,
16.1.3 Voltage breakdown for each puncture,
16.1.4 Average, minimum, and maximum voltage breakdown,
16.1.5 Procedure used (Method A or B), and
16.1.6 Temperature and relative humidity of test, if different from 6.1.
17. Precision and Bias
17.1 Precision—The overall estimates of the precision within laboratories (Sr) and the precision between laboratories (SR) for
j j
the determination of Dielectric Breakdown Voltage by Procedure A are given in Table 3 for three selected materials. These
estimates are based on a round robin of the three materials with six laboratories participating.
17.2 Bias—This test method has no bias because the value for dielectric breakdown voltage is determined solely in terms of this
test method.
TABLE 3 Estimated Precision of Dielectric Breakdown Voltage
Measurement
Nominal Value, (Sr) , (SR) ,
j j
Sleeving Type
Volts volts Volts volts Volts volts
Conditioned 18 h/23 °C/50 % RH
Acrylic 8480 802 1126
PVC 10980 983 1528
Silicone Rubber 10770 904 1616
Conditioned 96 h/23 °C/93 % RH
Acrylic 2048 197 828
PVC 8100 1003 2137
Silicone Rubber 8540 1367 2550
D350 − 21
BRITTLENESS TEMPERATURE
18. Significance and Use
18.1 This test method serves to measure the brittleness temperature of the sleeving. It is useful for comparative and quality control
purposes.
18.2 Results of this test have not been found to correlate with those obtained by bending or flexing around mandrels at low
temperatures. Brittleness temperatures determined for sleeving materials by this test are affected by differences in cross-sectional
dimensions and in specimen configuration, even if the materials have the same composition.
19. Procedure
19.1 Determine the brittleness temperature in accordance with Test Method D746, except as specified in 19.1.1 – 19.1.4.
19.1.1 For sleeving sizes 20 through 8, cut specimens in full section and 1.5 in. (38 mm) long.
19.1.2 For sleeving sizes 7 through 1 in. inside diameter, cut specimens 0.25 in. (6.4 mm) wide and 1.5 in. (38 mm) long with
the longer dimension parallel to the axis of the sleeving. Take care to avoid cutting the specimens from the edges of sleeving that
has been flattened during manufacture or storage.
19.1.3 Use only motor-driven or gravity-fall apparatus, such as described in Test Methods D876. Mount specimens so that the
striking edge of the apparatus contacts the film and not the braid.
19.1.4 Failure of a specimen is indicated by cracking of the film completely through to the braid, as determined by visual
examination.
20. Report
20.1 Report the following information:
20.1.1 Identification of the sleeving,
20.1.2 Brittleness temperature to the nearest °C,
20.1.3 Method of calculation (see Test Method D746),
20.1.4 Type of apparatus used, and
20.1.5 Number of specimens tested.
21. Precision and Bias
21.1 Precision—This test method has been in use for many years, but no information has been presented to ASTM upon which
to base a statement of precision. No activity has been planned to develop such information.
21.2 Bias—This test method has no bias because the value for brittleness temperature is determined solely in terms of this test
method.
FLAMMABILITY—METHOD A
22. Procedure—Determine the flammability in accordance with test method A in Test Methods D8355.
22.1 Determine the flammability in accordance with Test Methods D876. The results of this test give an indication of the tendency
of the material to burn in case of fire.
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FLAMMABILITY—METHOD B
23. Significance and Use
23.1 This test gives an indication of the relative rate at which materials that will burn will propagate a flame.
24. Apparatus
24.1 Bunsen burner.
24.2 Stopwatch.
25. Test Specimens
25.1 Cut at least three specimens from the material selected in accordance with Section 5.
23. Procedure—Determine the flammability in accordance with test method B in Test Methods D8355.
26.1 Mark a gage length of 1 in. (25 mm) on each test specimen approximately 0.5 in. (13 mm) from one end of the specimen.
Using a method that will not distort the test area, close the other end to prevent passage of air through the specimen during the
test.
26.2 Insert the open end of the sleeving into the side of the burner flame with the lower side of the sleeving about 0.5 in. (13 mm)
above the top of the burner. Rotate the specimen in the flame to ignite it uniformly. Remove the sleeving from the flame and hold
vertically in the air with the burning end uppermost.
26.3 Start the timer when the leading edge of the flame reaches the upper gage mark and observe the time in seconds for the
leading edge of the flame to travel down the specimen to the lower gage mark.
27. Report
27.1 Report the following information:
27.1.1 Identification of the sleeving, and
27.1.2 For each specimen, the time in seconds required to burn 1 in. (25.4 mm).
28. Precision and Bias
28.1 No statement is made about either the precision or the bias of this test method since the result merely states whether there
is conformance to the criteria for success as specified in the procedure.
DIELECTRIC BREAKDOWN VOLTAGE AFTER SHORT-TIME AGING
24. Significance and Use
24.1 This test method serves to indicate the resistance of sleeving to the effects of short-time exposure to elevated temperatures.
While this test method provides a means of determining continuity of quality and is useful as a lot acceptance test, it is not intended
to provide information regarding the thermal endurance of the sleeving (see Sections 3833 to 4439).
25. Test Specimens
25.1 Prepare five 90° bent test specimens as described in 15.2.1 and 15.2.2.
D350 − 21
26. Procedure
26.1 Condition the test specimens in an oven for a period of 96 h at a temperature 50 °C (90 °F) higher than the nominal
temperature index of the sleeving. Remove the specimens and allow to cool to room temperature. Apply the outer electrode and
determine the dielectric breakdown voltage in accordance with 14.2.
27. Report
27.1 Report the following information:
27.1.1 Identification of the sleeving,
27.1.2 Temperature of conditioning, and
27.1.3 Average, minimum, and maximum voltage breakdown values.
28. Precision and Bias
28.1 Precision—This test method has been in use for many years, but no information has been presented to ASTM upon which
to base a statement of precision. No activity has been planned to develop such information.
28.2 Bias—This test method has no bias because the value for dielectric breakdown voltage after short-time aging is determined
solely in terms of this test method.
OIL RESISTANCE
29. Test Specimens
29.1 Cut three specimens, each 3 in. (76 mm) long, from material selected in accordance with Section 5.
30. Procedure
30.1 Immerse the specimens for 24 h in ASTM Oil No. 2 as described in Test Method D471, the oil being maintained at a
temperature of 105 6 2 °C (221 6 3.6 °F). At the end of this period, remove the specimens from the oil, wipe off excess oil with
a clean cloth, and examine the specimens for deterioration as evidenced by blistering, splitting, flaking off of the film, and other
visual defects.
NOTE 2—Oil meeting Specification D3487 has been found suitable as a substitute for ASTM Oil No. 2.
30.2 Determine the degree of swelling by measurements of wall thickness as specified in 9.2.
31. Report
31.1 Report the following information:
31.1.1 Identification of the sleeving,
31.1.2 Evidence of deterioration of the sleeving,
31.1.3 Percentage of increase in wall thickness, and
31.1.4 Type of oil used (if other than ASTM No. 2).
32. Precision and Bias
32.1 Precision—This test method has been in use for many years, but no information has been presented to ASTM upon which
to base a statement of precision. No activity has been planned to develop such information.
D350 − 21
32.2 Bias—This test method has no bias because the value for oil resistance is determined solely in terms of this test method.
THERMAL ENDURANCE
33. Summary of Test Method
33.1 This test method describes preparation of specimens, aging of specimens at elevated temperatures, and periodic testing of
breakdown voltage. The data obtained are used to plot a regression line on logarithmic-time versus reciprocal-absolute-temperature
coordinates from which the thermal endurance in terms of a temperature index is derived.
34. Significance and Use
34.1 This test method is useful in determining the relative thermal endurance of sleeving initially capable of being bent 90°
without splitting.
34.2 The criterion of failure by this test method is reduction of breakdown voltage of the sleeving below a value of 3500 V. It is
believed that this embodies several modes of failure, such as cracking by embrittlement, volatilization, porosity, and crazing, which
are not indepen
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