ASTM D3294-22

Standard Specification for Polytetrafluoroethylene (PTFE) Resin Molded Sheet and Molded Basic Shapes

ABSTRACT
This specification establishes the requirements and test methods for the material, dimensions, and workmanship, and the physical and electrical properties of molded sheet manufactured from polytetrafluoroethylene (PTFE) resin molding materials and molded basic shapes made from resin molding and extrusion materials. The sheet or molded basic shape shall be made from unpigmented PTFE and shall be free from foreign matters. Each of the samples shall undergo visual and dimensional inspection to verify their compliance with the standard requirements. The specimens shall conform to the following physical and electrical property requirements: tensile strength; elongation; dielectric strength; specific gravity; porosity; and melting point. Examination for internal defects shall also be conducted to ensure that the specimens are free from microscopic cracks, voids, inclusions, and other surface defects that might affect the serviceability of the materials.
SCOPE
1.1 This specification establishes requirements and methods of test for the material, dimensions, and workmanship, and the physical and electrical properties of molded sheet in minimum thicknesses of 0.794 mm (1/32 in.) manufactured from PTFE resin molding materials defined in Specification D4894.  
1.2 This specification also establishes requirements for molded basic shapes made from molding materials. This specification is for products 300 mm (12 in.) or less in a dimension parallel to and 12.7 mm (0.5 in.) or greater in the dimension perpendicular to the direction of the applied molding pressure.  
1.3 The values stated in SI units are to be regarded as the standard.  
1.4 The following precautionary caveat pertains only to the test method portion, Section 7, of this specification. 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. Special attention is called to 13.2, 13.3, 13.6, 13.8, and A1.  
Note 1: There is no known ISO equivalent to this standard.  
1.5 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.

General Information

• Status: Published
• Publication Date: 30-Jun-2022
• ICS: 83.140.99 - Other rubber and plastics products
• Technical Committee: D20 - Plastics
• Drafting Committee: D20.15 - Thermoplastic Materials

Relations

• Refers: ASTM D883-24 - Standard Terminology Relating to Plastics
• Effective Date: 01-Feb-2024
• Refers: ASTM D883-23 - Standard Terminology Relating to Plastics
• Effective Date: 01-Nov-2023
• Refers: ASTM D374/D374M-23 - Standard Test Methods for Thickness of Solid Electrical Insulation
• Effective Date: 01-Oct-2023
• Refers: ASTM D149-20 - Standard Test Method for Dielectric Breakdown Voltage and Dielectric Strength of Solid Electrical Insulating Materials at Commercial Power Frequencies
• Effective Date: 01-Jan-2020
• Refers: ASTM D883-20 - Standard Terminology Relating to Plastics
• Effective Date: 01-Jan-2020
• Refers: ASTM D883-19c - Standard Terminology Relating to Plastics
• Effective Date: 01-Aug-2019
• Refers: ASTM D4894-19 - Standard Specification for Polytetrafluoroethylene (PTFE) Granular Molding and Ram Extrusion Materials
• Effective Date: 01-May-2019
• Refers: ASTM D883-19a - Standard Terminology Relating to Plastics
• Effective Date: 15-Apr-2019
• Refers: ASTM D883-19 - Standard Terminology Relating to Plastics
• Effective Date: 01-Feb-2019
• Refers: ASTM D883-18a - Standard Terminology Relating to Plastics
• Effective Date: 01-Dec-2018
• Refers: ASTM D883-18 - Standard Terminology Relating to Plastics
• Effective Date: 01-Nov-2018
• Refers: ASTM D1708-18 - Standard Test Method for Tensile Properties of Plastics by Use of Microtensile Specimens
• Effective Date: 01-Oct-2018
• Refers: ASTM D1600-18 - Standard Terminology for Abbreviated Terms Relating to Plastics (Withdrawn 2024)
• Effective Date: 01-Jan-2018
• Refers: ASTM D883-17 - Standard Terminology Relating to Plastics
• Effective Date: 15-Aug-2017
• Refers: ASTM D3892-15 - Standard Practice for Packaging/Packing of Plastics
• Effective Date: 01-Sep-2015

Overview

ASTM D3294-22: Standard Specification for Polytetrafluoroethylene (PTFE) Resin Molded Sheet and Molded Basic Shapes sets out requirements and test methods for molded sheets and basic shapes fabricated from PTFE resin molding and extrusion materials. This international standard, developed by ASTM, serves as a critical reference for manufacturers, suppliers, and users in the plastics and fluoropolymer industries, ensuring consistent quality, reliability, and performance in PTFE-based materials and components.

This specification covers physical, electrical, and dimensional requirements for PTFE molded sheets (minimum thickness 0.794 mm) and molded basic shapes no larger than 300 mm in one axis and at least 12.7 mm in the perpendicular axis. It also establishes standards for material purity, mechanical and electrical properties, internal defect inspection, and marking and packaging.

Key Topics

• Material Requirements: Products must be made from unpigmented PTFE resin, free from foreign matter and inclusions.
• Dimensional Specifications: Defines tolerances and stability for multiple shapes and thicknesses to support precision manufacturing.
• Visual and Internal Inspection: Mandates visual checks and radiographic examination to identify microscopic cracks, voids, or other defects affecting serviceability.
• Mechanical Properties: Includes mandatory tests for tensile strength and elongation to ensure mechanical performance.
• Electrical Properties: Outlines dielectric strength requirements vital for insulating applications.
• Porosity and Specific Gravity: Specifies porosity (where required) and density testing to ensure structural integrity.
• Thermal Properties: Covers parameters like melting point and dimensional stability under heat exposure.

Applications

ASTM D3294-22 is widely adopted in industries demanding high-performance, chemically inert materials. PTFE molded sheet and shapes are essential in:

• Electrical and Electronics: Used as insulation in high-voltage equipment and components, relying on PTFE’s excellent dielectric properties.
• Mechanical Seals and Bearings: PTFE’s chemical resistance and low friction make it ideal for gaskets, bushings, and bearing surfaces.
• Chemical Processing: Liners and components for vessels, tanks, and pipes benefit from PTFE’s resistance to aggressive chemicals.
• Medical Devices: Non-reactive molded PTFE is used in certain medical instruments and laboratory equipment.
• Food Processing: Selected grades are utilized where inert, non-stick performance is crucial.

The standard also provides guidance on ordering, marking, packaging, and supplier certification to support traceability and quality control for these critical applications.

Related Standards

For a complete approach to the specification, testing, and procurement of PTFE materials, the following ASTM standards are commonly referenced alongside ASTM D3294-22:

• ASTM D4894: Specification for PTFE Molding and Ram Extrusion Materials
• ASTM D638: Test Method for Tensile Properties of Plastics
• ASTM D149: Test Method for Dielectric Strength of Solid Electrical Insulating Materials
• ASTM D792: Test Methods for Density and Specific Gravity of Plastics
• ASTM D374/D5947: Test Methods for Thickness and Physical Dimensions of Solid Plastics
• ASTM D883 & D1600: Terminology for Plastics and Abbreviated Terms
• ASTM D3892: Practice for Packaging of Plastics
• ASTM D4591: Determining Temperatures and Heats of Transitions of Fluoropolymers

Key benefits of compliance: Assures end-users and specifiers of dependable quality and property consistency, supports regulatory and safety requirements, and improves supply chain communication for PTFE molded products.

Keywords: ASTM D3294, PTFE sheet, molded shapes, polytetrafluoroethylene, fluoropolymer, dielectric strength, mechanical properties, chemical resistance, plastics standard.

Standards Content (Sample)

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.
Designation:D3294 −22
Standard Specification for
Polytetrafluoroethylene (PTFE) Resin Molded Sheet and
Molded Basic Shapes
This standard is issued under the fixed designation D3294; 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* 2. Referenced Documents
2.1 ASTM Standards:
1.1 This specification establishes requirements and methods
D149 Test Method for Dielectric Breakdown Voltage and
of test for the material, dimensions, and workmanship, and the
DielectricStrengthofSolidElectricalInsulatingMaterials
physical and electrical properties of molded sheet in minimum
at Commercial Power Frequencies
thicknesses of 0.794 mm ( ⁄32 in.) manufactured from PTFE
D374/D374M Test Methods for Thickness of Solid Electri-
resin molding materials defined in Specification D4894.
cal Insulation
1.2 This specification also establishes requirements for
D618 Practice for Conditioning Plastics for Testing
molded basic shapes made from molding materials. This
D638 Test Method for Tensile Properties of Plastics
specification is for products 300 mm (12 in.) or less in a
D792 Test Methods for Density and Specific Gravity (Rela-
dimension parallel to and 12.7 mm (0.5 in.) or greater in the
tive Density) of Plastics by Displacement
dimension perpendicular to the direction of the applied mold-
D883 Terminology Relating to Plastics
ing pressure.
D1600 Terminology forAbbreviatedTerms Relating to Plas-
tics
1.3 The values stated in SI units are to be regarded as the
D1708 Test Method forTensile Properties of Plastics by Use
standard.
of Microtensile Specimens
1.4 The following precautionary caveat pertains only to the
D3892 Practice for Packaging/Packing of Plastics
test method portion, Section 7, of this specification. This
D4591 Test Method for Determining Temperatures and
standard does not purport to address all of the safety concerns,
Heats of Transitions of Fluoropolymers by Differential
if any, associated with its use. It is the responsibility of the user
Scanning Calorimetry
of this standard to establish appropriate safety, health, and
D4894 Specification for Polytetrafluoroethylene (PTFE)
environmental practices and determine the applicability of
Granular Molding and Ram Extrusion Materials
regulatory limitations prior to use.Specialattentioniscalledto
D5947 Test Methods for Physical Dimensions of Solid
13.2, 13.3, 13.6, 13.8, and A1.
Plastics Specimens
E94/E94M Guide for Radiographic Examination Using In-
NOTE 1—There is no known ISO equivalent to this standard.
dustrial Radiographic Film
1.5 This international standard was developed in accor-
IEEE/ASTM SI-10 American National Standard for Use of
dance with internationally recognized principles on standard-
theInternationalSystemofUnits(SI):TheModernMetric
ization established in the Decision on Principles for the
System
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
3. Terminology
Barriers to Trade (TBT) Committee.
3.1 Definitions:
3.1.1 Definitions are in accordance with Terminology D883
unless otherwise specified.
This specification is under the jurisdiction of ASTM Committee D20 on
Plastics and is the direct responsibility of Subcommittee D20.15 on Thermoplastic
Materials (Section D20.15.12). For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved July 1, 2022. Published July 2022. Originally approved contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
in 1974. Last previous edition approved in 2015 as D3294 - 15. DOI: 10.1520/ Standards volume information, refer to the standard’s Document Summary page on
D3294-22. the ASTM website.
*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
D3294−22
3.1.2 lot, n—one continuous production run or a uniform 5. Ordering Information
blend of two or more production runs of one size sheet or
5.1 The molded sheet or basic shapes covered in this
molded basic shape.
specification shall be ordered stating the type, grade, and class
3.2 Abbreviations: and that they meet the requirements of this specification.
3.2.1 Abbreviations are in accordance with Terminology
D1600. 6. Materials
6.1 The sheet or molded basic shape from Types I, II, III, or
4. Classification
IV shall be made from unpigmented PTFE as free of foreign
4.1 This specification covers the following four types of
matter as commercially practical.
molded basic sheets and shapes:
4.1.1 Type I—Premium; normally used for exacting
7. Requirements
electrical, mechanical, or chemical applications.
7.1 The sheet covered by this specification shall meet the
4.1.2 Type II—General purpose; for electrical, mechanical,
physical and electrical requirements specified in Table 1 when
and chemical applications not requiring premium material.
tested by the methods given in Section 13.
4.1.3 Type III—Mechanical Grade; for non-critical
7.2 The molded basic shapes covered by this specification
chemical, electrical, and mechanical applications.
shall meet the physical and electrical requirements specified in
4.1.4 Type IV—Utility; having no electrical requirements
Table 2 when tested by the test methods given in Section 13.
and with mechanical properties at a lower level.
7.2.1 Melting Point—the melting point of all types of sheet
4.2 Types I, II, and III shall be subdivided into two grades
and molded basic shapes shall be 327 6 10°C when tested in
as follows:
accordance with paragraph 13.8.
4.2.1 Grade 1—made only from virgin resin.
4.2.2 Grade 2—made using reprocessed resin.
8. Dimensions
4.3 The grades shall be further subdivided into four classes
8.1 The size, shape, dimensional tolerances, and dimen-
as follows:
sional stability shall be as specified in the contract or order.
4.3.1 Class A—resistant to thermal dimensional change not
8.2 The tolerance on length and width shall be plus 6.3 mm
exceeding 0.5 %.
( ⁄4 in.), minus 0 mm (0 in.).
4.3.2 Class B—thermal dimensional change not exceeding
5.0 %.
9. Workmanship, Finish, and Appearance
4.3.3 Class C—no requirement for thermal dimensional
change.
9.1 Color—Type I shall be white to translucent. Types II,
4.3.4 Class D—as agreed by the processor and customer.
III, and IV are typically white, but vary to off white or light
gray. For Types II, III, and IV occasional small gray, brown, or
4.4 A one-line system shall be used to specify materials
black spots shall not be considered as cause for rejection.
covered by this specification. The system uses predefined cells
to refer to specific aspects of this specification, as illustrated
9.2 Finish—The material shall be as free as is commercially
below.
practical from surface blisters, wrinkles, cracks and other
surface defects that might affect its serviceability. It shall also
Specification
becommerciallyfreeofmacroscopicvoids,cracks,andforeign
Standard Number : Type : Grade : Class : Special
Block : : : : Notes
inclusions.
:::::
9.3 Internal Defects—The moldings shall be as free as is
Example: Specification D3294 – 03, I I A
commercially practical of microscopic voids, cracks, and
For this example, the line callout would be Specification
foreign inclusions.
D3294 – 03, 11A and would specify premium virgin form of
polytetrafluoroethylene that has all of the properties listed for
that Type, Grade, and Class in the appropriate specified
A
properties, tables, or both, in the specification identified. A
TABLE 1 Physical and Electrical Requirements for PTFE Sheets
comma is used as the separator between the standard Number
Dielectric
Tensile Elonga-
C
B
Strength Specific D
A A
and the Type. Separators are not needed between the Type,
Types Porosity
Strength tion (min)
(min) Volts Gravity
(min) psi Percent
Grade, and Class. Provision for Special Notes is included so Per Mill
E
that other information shall be provided when required. An
I 4500 300 600 2.15 to 2.18 Zero penetration
II 3000 225 500 2.14 to 2.19 Not required
example would be in Specification D3295 where dimensions
III 2000 150 300 2.13 to 2.19 Not required
and tolerances are specified for each AWG size within Type
IV 1300 75 Not required 2.13 to 2.20 Not required
andClass.WhenSpecialNotesareused,theyshallbepreceded
A
See 13.2.
B
by a comma.
See 13.3
C
See 13.4
D
See 13.6
E
PTFE sheet used for tank lining shall be Type I but shall have a specific gravity
See the ASTM Form and Style Manual. Available from ASTM International
of 2.19 to 2.22.
Headquarters.
D3294−22
TABLE 2 Physical and Electrical Requirements for Basic Shapes
inspected to verify their compliance with the requirements of
Dielectric the standard. Occasional superficial flaws in PTFE sheet or
Tensile Strength Elongation %
Types Strength Volts Specific Gravity
moldedbasicshapesshallbeinterpretedasneitheraffectingthe
psi (min) (min)
per mil (min)
porosity nor soundness of the molding. Such flaws are
I 4800 325 1200 2.14 to 2.18
scratches, edge cracks, and the adherence of resin flakes. Such
II 3200 240 850 2.14 to 2.19
III 1500 75 250 2.13 to 2.20
indications shall not be cause for rejection.
IV 1500 75 Not required 2.13 to 2.20
13.2 Tensile Strength and Elongation—Determine the ulti-
mate tensile strength and elongation in accordance with Test
Method D638 except as follows:
10. Sampling
13.2.1 Cut five micro-specimens with the steel rule die and
10.1 Sampling shall be statistically adequate to satisfy the
the dimensions shown in Fig. 1 using a hydraulic or mechani-
requirements of 15.1
cal press. When cutting a specimen, back it by a hard surface
board such as masonite or equal with a piece of thin cardboard
11. Number of Tests
between said hard surface and sample.
11.1 Routine lot inspection tests shall consist of all the tests
13.2.2 Testing shall be at a speed of 50.8 mm (2 in.)/min.
specified in Table 1, Table 2,or Table 3.
13.2.3 Determine elongation by using an initial jaw separa-
tion of 22.2 mm (0.875 in.) and expressed as a percentage of
11.2 The tests listed in Table 1 and Table 2, as they apply,
the initial jaw separation.
aresufficienttoestablishconformityofthePTFEsheetorbasic
13.2.4 Alternative Specimens—When the shape of the
shapes to this specification. When the number of test speci-
sample does not permit making the micro-specimen as speci-
mensisnotstatedinthetestmethod,singledeterminationshall
fied in 13.2.1 prepare specimens by turning a 0.8-mm ( ⁄32-in.)
be made. If more than single determinations and separate
thick-walled tube from the shape, and cutting dumbbells from
portions of the same sample are made, the results shall be
averaged. The single or average result shall conform to the the tube wall in a direction perpendicular to the applied
molding pressure, that is, with the long axis of the dumbbell
requirements prescribed in this specification.
parallel to the circumference of the tube. Lathe-turn the tube in
11.3 The properties listed in the Appendix X1 provide
such a manner that the specimen is taken from the center of the
additional information. The data shown are informational only
original wall thickness. In the case of a rod, remove the outer
and shall not be used for specification purposes.
1.6 mm ( ⁄16 in.) before finish turning the outer diameter of the
tube. Turn both inside and outside surfaces with a fine lathe
12. Test Conditions
feed and sharp tools to permit the smoothest possible finish.
12.1 Conditioning of Specimens—Unless otherwise speci-
13.2.5 Cutsheets1.6mm( ⁄16in.)orunderinthickness,five
fied in this specification, the test specimens shall be condi-
micro-specimens with the steel rule die and the dimensions
tioned in accordance with Procedure A of Practice D618 for a
shown in Fig. 1 using a hydraulic or mechanical press.
perio
...

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: D3294 − 15 D3294 − 22
Standard Specification for
Polytetrafluoroethylene (PTFE) Resin Molded Sheet and
Molded Basic Shapes
This standard is issued under the fixed designation D3294; 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*
1.1 This specification establishes requirements and methods of test for the material, dimensions, and workmanship, and the
physical and electrical properties of molded sheet in minimum thicknesses of 0.794 mm ( ⁄32 in.) manufactured from PTFE resin
molding materials defined in Specification D4894.
1.2 This specification also establishes requirements for molded basic shapes made from molding materials. This specification is
for products 300 mm (12 in.) or less in a dimension parallel to and 12.7 mm (0.5 in.) or greater in the dimension perpendicular
to the direction of the applied molding pressure.
1.3 The values stated in SI units are to be regarded as the standard.
1.4 The following precautionary caveat pertains only to the test method portion, Section 7, of this specification. 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. Special attention is called to 13.2, 13.3, 13.6, 13.8, and A1.
NOTE 1—There is no known ISO equivalent to this standard.
1.5 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
D374D374/D374M Test Methods for Thickness of Solid Electrical Insulation (Metric) D0374_D0374M
D618 Practice for Conditioning Plastics for Testing
D638 Test Method for Tensile Properties of Plastics
D792 Test Methods for Density and Specific Gravity (Relative Density) of Plastics by Displacement
D883 Terminology Relating to Plastics
This specification is under the jurisdiction of ASTM Committee D20 on Plastics and is the direct responsibility of Subcommittee D20.15 on Thermoplastic Materials
(Section D20.15.12).
Current edition approved Sept. 1, 2015July 1, 2022. Published September 2015July 2022. Originally approved in 1974. Last previous edition approved in 20092015 as
D3294 - 09.D3294 - 15. DOI: 10.1520/D3294-15.10.1520/D3294-22.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
*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
D3294 − 22
D1600 Terminology for Abbreviated Terms Relating to Plastics
D1708 Test Method for Tensile Properties of Plastics by Use of Microtensile Specimens
D3892 Practice for Packaging/Packing of Plastics
D4591 Test Method for Determining Temperatures and Heats of Transitions of Fluoropolymers by Differential Scanning
Calorimetry
D4894 Specification for Polytetrafluoroethylene (PTFE) Granular Molding and Ram Extrusion Materials
D5947 Test Methods for Physical Dimensions of Solid Plastics Specimens
E94E94/E94M Guide for Radiographic Examination Using Industrial Radiographic Film
IEEE/ASTM SI-10 American National Standard for Use of the International System of Units (SI): The Modern Metric System
3. Terminology
3.1 Definitions:
3.1.1 Definitions are in accordance with Terminology D883 unless otherwise specified.
3.1.2 lot, n—one continuous production run or a uniform blend of two or more production runs of one size sheet or molded basic
shape.
3.2 Abbreviations:
3.2.1 Abbreviations are in accordance with Terminology D1600.
4. Classification
4.1 This specification covers the following four types of molded basic sheets and shapes:
4.1.1 Type I—Premium; normally used for exacting electrical, mechanical, or chemical applications.
4.1.2 Type II—General purpose; for electrical, mechanical, and chemical applications not requiring premium material.
4.1.3 Type III—Mechanical Grade; for non-critical chemical, electrical, and mechanical applications.
4.1.4 Type IV—Utility; having no electrical requirements and with mechanical properties at a lower level.
4.2 Types I, II, and III shall be subdivided into two grades as follows:
4.2.1 Grade 1—made only from virgin resin.
4.2.2 Grade 2—made using reprocessed resin.
4.3 The grades shall be further subdivided into threefour classes as follows:
4.3.1 Class A—resistant to thermal dimensional change not exceeding 0.5 %.
4.3.2 Class B—thermal dimensional change not exceeding 5.0 %.
4.3.3 Class C—no requirement for thermal dimensional change.
4.3.4 Class D—as agreed by the processor and customer.
4.4 A one-line system shall be used to specify materials covered by this specification. The system uses predefined cells to refer
to specific aspects of this specification, as illustrated below.
Specification
Standard Number : Type : Grade : Class : Special
Block : : : : Notes
: : : : :
Example: Specification D3294 – 03, I I A
D3294 − 22
For this example, the line callout would be Specification D3294 – 03, 11A and would specify premium virgin form of
polytetrafluoroethylene that has all of the properties listed for that Type, Grade, and Class in the appropriate specified properties,
tables, or both, in the specification identified. A comma is used as the separator between the standard Number and the Type.
Separators are not needed between the Type, Grade, and Class. Provision for Special Notes is included so that other information
shall be provided when required. An example would be in Specification D3295 where dimensions and tolerances are specified for
each AWG size within Type and Class. When Special Notes are used, they shall be preceded by a comma.
5. Ordering Information
5.1 The molded sheet or basic shapes covered in this specification shall be ordered stating the type, grade, and class and that they
meet the requirements of this specification.
6. Materials
6.1 The sheet or molded basic shape from Types I, II, III, or IV shall be made from unpigmented PTFE as free of foreign matter
as commercially practical.
7. Requirements
7.1 The sheet covered by this specification shall meet the physical and electrical requirements specified in Table 1 when tested
by the methods given in Section 13.
7.2 The molded basic shapes covered by this specification shall meet the physical and electrical requirements specified in Table
2 when tested by the test methods given in Section 13.
7.2.1 Melting Point—the melting point of all types of sheet and molded basic shapes shall be 327 6 10°C when tested in
accordance with paragraph 13.8.
8. Dimensions
8.1 The size, shape, dimensional tolerances, and dimensional stability shall be as specified in the contract or order.
8.2 The tolerance on length and width shall be plus 6.3 mm ( ⁄4 in.), minus 0 mm (0 in.).
9. Workmanship, Finish, and Appearance
9.1 Color—Type I shall be white to translucent. Types II, III, and IV are typically white, but vary to off white or light gray. For
Types II, III, and IV occasional small gray, brown, or black spots shall not be considered as cause for rejection.
9.2 Finish—The material shall be as free as is commercially practical from surface blisters, wrinkles, cracks and other surface
defects that might affect its serviceability. It shall also be commercially free of macroscopic voids, cracks, and foreign inclusions.
A
TABLE 1 Physical and Electrical Requirements for PTFE Sheets
Dielectric
Tensile Elonga-
C
B
Strength Specific D
A A
Types Porosity
Strength tion (min)
(min) Volts Gravity
(min) psi Percent
Per Mill
E
I 4500 300 600 2.15 to 2.18 Zero penetration
II 3000 225 500 2.14 to 2.19 Not required
III 2000 150 300 2.13 to 2.19 Not required
IV 1300 75 Not required 2.13 to 2.20 Not required
A
See 13.2.
B
See 13.3
C
See 13.4
D
See 13.6
E
PTFE sheet used for tank lining shall be Type I but shall have a specific gravity
of 2.19 to 2.22.
See the ASTM Form and Style Manual. Available from ASTM International Headquarters.
D3294 − 22
TABLE 2 Physical and Electrical Requirements for Basic Shapes
Dielectric
Tensile Strength Elongation %
Types Strength Volts Specific Gravity
psi (min) (min)
per mil (min)
I 4800 325 1200 2.14 to 2.18
II 3200 240 850 2.14 to 2.19
III 1500 75 250 2.13 to 2.20
IV 1500 75 Not required 2.13 to 2.20
9.3 Internal Defects—The moldings shall be as free as is commercially practical of microscopic voids, cracks, and foreign
inclusions.
10. Sampling
10.1 Sampling shall be statistically adequate to satisfy the requirements of 15.1
11. Number of Tests
11.1 Routine lot inspection tests shall consist of all the tests specified in Table 1, Table 2, or Table 3.
11.2 The tests listed in Table 1 and Table 2, as they apply, are sufficient to establish conformity of the PTFE sheet or basic shapes
to this specification. When the number of test specimens is not stated in the test method, single determination shall be made. If
more than single determinations and separate portions of the same sample are made, the results shall be averaged. The single or
average result shall conform to the requirements prescribed in this specification.
11.3 The properties listed in the Appendix X1 provide additional information. The data shown are informational only and shall
not be used for specification purposes.
12. Test Conditions
12.1 Conditioning of Specimens—Unless otherwise specified in this specification, the test specimens shall be conditioned in
accordance with Procedure A of Practice D618 for a period of at least four h prior to test.
12.2 Standard Temperature—Unless otherwise specified, the tests shall be conducted at the standard laboratory temperature of
23°C 6 2°C (73.4°F 6 3.6°F). Since the sheet or molded basic shape does not absorb water, the maintenance of constant humidity
during testing is not important.
13. Test Methods
13.1 Visual and Dimensional Inspection—Each of the sample PTFE sheets or molded basic shapes selected in accordance with
Section 10 shall be visually and dimensionally inspected to verify their compliance with the requirements of the standard.
TABLE 3 Nominal Thickness and Tolerances for PTFE Sheets
Thickness Tolerance Thickness Tolerance Thickness Tolerance
Inch Inch Inch Inch Inch Inch
1 1 1
⁄32 +0.015 ⁄4 +0.030 1 ⁄4 +0.102
−0.005 −0.015 −0.051
1 3 1
⁄16 +0.015 ⁄8 +0.038 1 ⁄2 +0.118
−0.005 −0.019 −0.059
3 1 3
⁄32 +0.020 ⁄2 +0.046 1 ⁄4 +0.134
−0.005 −0.022 −0.067
1 5
⁄8 +0.016 ⁄8 +0.054 2 +0.150
−0.008 −0.027 −0.075
5 3
⁄32 +0.018 ⁄4 +0.070 Over 2 +10 %
−0.009 −0.035 −10 %
⁄16 +0.022 1 +0.087
−0.011 −0.043
D3294 − 22
Occasional superficial flaws in PTFE sheet or molded basic shapes shall be interpreted as neither affecting the porosity nor
soundness of the molding. Such flaws are scratches, edge cracks, and the adherence of resin flakes. Such indications shall not be
cause for rejection.
13.2 Tensile Strength and Elongation—Determine the ultimate tensile strength and elongation in accordance with Test Method
D638 except as follows:
13.2.1 Cut five micro-specimens with the steel rule die and the dimensions shown in Fig. 1 using a hydraulic or mechanical press.
When cutting a specimen, back it by a hard surface board such as masonite or equal with a piece of thin cardboard between said
hard surface and sample.
13.2.2 Testing shall be at a speed of 50.8 mm (2 in.)/min.
13.2.3 Determine elongation by using an initial jaw separation of 22.2 mm (0.875 in.) and expressed as a percentage of the initial
jaw separation.
13.2.4 Alternative Specimens
...