ASTM D7093-19

Standard Test Method for Formability of Thin Film Organic Coatings on Steel Over a Biaxially Stretched Dome

SIGNIFICANCE AND USE
5.1 The results of the combined deformation and tape test are related to the ability of the coated metal to withstand stamping in factory applications.  
5.2 This test can be used to determine or control the manufacturing process or for coatings development work to improve the product.  
5.3 It should be recognized that variability in the results persists due to the test conditions and forming machine variations.
SCOPE
1.1 This test method covers the evaluation of the formability and adhesion of factory applied thin film organic coatings on steel having coating thicknesses of 2.5 to 10 microns (0.10 to 0.40 mils) typical of those used in the coil coating industry.  
1.2 The degree of oil removal prior to forming, the techniques of taping, and differences in adhesive strength of the tape can affect the adhesion rating.  
1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.  
1.4 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. For a specific hazard statement, see Section 7.  
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-Apr-2019
• ICS: 25.220.60 - Organic coatings
• Technical Committee: D01 - Paint and Related Coatings, Materials, and Applications
• Drafting Committee: D01.53 - Coil Coated Metal

Relations

• Replaces: ASTM D7093-13 - Standard Test Method for Formability of Thin Film Organic Coatings on Steel Over a Biaxially Stretched Dome
• Effective Date: 01-May-2019
• Refers: ASTM D3330/D3330M-04(2010) - Standard Test Method for Peel Adhesion of Pressure-Sensitive Tape
• Effective Date: 01-Apr-2010
• Refers: ASTM D3330/D3330M-04 - Standard Test Method for Peel Adhesion of Pressure-Sensitive Tape
• Effective Date: 01-Oct-2004
• Refers: ASTM D3330/D3330M-02 - Standard Test Method for Peel Adhesion of Pressure-Sensitive Tape
• Effective Date: 10-Oct-2002
• Refers: ASTM D3330/D3330M-00 - Standard Test Method for Peel Adhesion of Pressure-Sensitive Tape
• Effective Date: 10-Oct-2000
• Referred By: ASTM D3794-22 - Standard Guide for Testing Coil Coatings
• Effective Date: 01-May-2019

Overview

ASTM D7093-19 is a key international standard developed by ASTM International for evaluating the formability and adhesion of thin film organic coatings on steel. This method is tailored for coatings with thicknesses from 2.5 to 10 microns, typical in the coil coating industry. The primary test simulates conditions that coated steel may experience during factory stamping and forming, providing valuable data for manufacturers, process controllers, and coating developers. The test includes biaxial stretching of a dome, followed by an adhesive tape pull to rate coating adhesion.

Key Topics

• Test Method: Utilizes biaxial stretching of a dome, followed by a tape test to assess coating adhesion. The results are compared against photographic standards for consistency.
• Specimen Preparation: Coated steel specimens must be properly prepped, free from oil, grease, rust, and burrs. Conditioning requirements ensure reproducibility.
• Adhesion Rating: Adhesive tape is applied to the formed dome area to determine the degree of coating removal, using visual comparison standards.
• Repeatability and Reproducibility: The standard acknowledges variability due to test conditions, machine differences, and operator technique. Repeatability within a laboratory and between different laboratories falls within defined limits.
• Safety Considerations: Users must ensure suitable safety, health, and environmental practices as the standard does not comprehensively address all possible hazards.

Applications

The ASTM D7093-19 test method is widely used in the following areas:

• Coil Coating Industry: Evaluating the performance and reliability of coil-coated steels in forming operations.
• Manufacturing Process Control: Assists in maintaining product quality by simulating factory stamping processes and predicting coating behavior under real-world conditions.
• Product Development: Enables R&D teams to assess and improve the formability and adhesion of new or modified thin film organic coatings.
• Quality Assurance: Offers an objective, standardized means to compare coating adhesion and to identify inconsistencies or potential failures before products reach the market.
• Regulatory Compliance: Supports adherence to both national and international quality and performance specifications for coated steel products.

Related Standards

Several other ASTM standards and references are complementary to or referenced by ASTM D7093-19:

• ASTM D3330/D3330M: Test Method for Peel Adhesion of Pressure-Sensitive Tape, used within D7093 to quantify tape adhesion strength.
• Pictorial Standards of Coating Defects: Crucial for visual comparison and adhesion rating after the tape test.
• Coil Coating Standards: Other standards developed by ASTM Committee D01, particularly those under Subcommittee D01.53 on Coil Coated Metal.

Practical Value

The ASTM D7093-19 standard is essential for industries where the durability and adhesion of organic coatings on steel are critical to performance and longevity. By following a defined, reproducible methodology, manufacturers and laboratories can ensure their products meet rigorous requirements and perform reliably under deformation processes common in automotive, appliance, and construction applications.

In summary, ASTM D7093-19 ensures consistency, reliability, and objectivity in the evaluation of thin film organic coatings, supporting innovation, quality control, and regulatory compliance across the coated steel supply chain.

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: D7093 − 19
Standard Test Method for
Formability of Thin Film Organic Coatings on Steel Over a
Biaxially Stretched Dome
This standard is issued under the fixed designation D7093; 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 2.2 Other Document:
Pictorial Standards of Coating Defects
1.1 Thistestmethodcoverstheevaluationoftheformability
and adhesion of factory applied thin film organic coatings on
3. Terminology
steel having coating thicknesses of 2.5 to 10 microns (0.10 to
3.1 Definitions of Terms Specific to This Standard:
0.40 mils) typical of those used in the coil coating industry.
3.1.1 dome height, n—the height of the dome formed in the
1.2 The degree of oil removal prior to forming, the tech-
test.
niques of taping, and differences in adhesive strength of the
3.1.2 indenting ball diameter, n—the diameter of the
tape can affect the adhesion rating.
spherical-ended penetrator (ball) used to deform the specimen.
1.3 The values stated in SI units are to be regarded as the
3.1.2.1 Discussion—The 41 mm (1.625 in.) diameter ball
standard. The values given in parentheses are for information
was selected because it minimizes the variability in the
only.
localized peak strain. This size ball is commercially available
and is as large as most testing machines can accommodate.
1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
3.1.3 percent strain, n—the percent elongation of scribed
responsibility of the user of this standard to establish appro-
gauge lengths after forming.
priate safety, health, and environmental practices and deter-
3.1.3.1 Discussion—For the draw height of 13 mm (0.512
mine the applicability of regulatory limitations prior to use.
in.), using a 41 mm diameter ball, the localized peak strain is
For a specific hazard statement, see Section 7.
about 19 % (see Fig. 1).
1.5 This international standard was developed in accor-
4. Summary of Test Method
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
4.1 A coated specimen is biaxially stretched a given dis-
Development of International Standards, Guides and Recom-
tance in an appropriate machine, adhesive tape is applied to the
mendations issued by the World Trade Organization Technical
deformed area (dome) and then pulled off, and the amount of
Barriers to Trade (TBT) Committee.
coating removed is compared with a photographic standard to
determine the coating adhesion rating.
2. Referenced Documents
5. Significance and Use
2.1 ASTM Standards:
5.1 The results of the combined deformation and tape test
D3330/D3330M Test Method for PeelAdhesion of Pressure-
are related to the ability of the coated metal to withstand
Sensitive Tape
stamping in factory applications.
5.2 This test can be used to determine or control the
1 manufacturing process or for coatings development work to
This test method is under the jurisdiction of ASTM Committee D01 on Paint
and Related Coatings, Materials, andApplications and is the direct responsibility of improve the product.
Subcommittee D01.53 on Coil Coated Metal.
Current edition approved May 1, 2019. Published June 2019. Originally
approved in 2004. Last previous edition approved in 2013 as D7093 – 13. DOI: Copies of the pictorial photographic reference standard are contained in the
10.1520/D7093-19. publication Pictorial Standards of Coatings Defects and may be obtained from the
For referenced ASTM standards, visit the ASTM website, www.astm.org, or Federation of Societies for CoatingsTechnology, 492 Norristown Rd., Blue Bell, PA
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM 19422. The silver halide gelatin photographs are intended to be the only primary
Standards volume information, refer to the standard’s Document Summary page on reference standards for this test method. The reproductions of them in this test
the ASTM website. method are for the purpose of illustration only.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7093 − 19
the required height is obtained, and clamping arrangement to
hold the specimen with a minimum pressure of 8.9 kN (2000
lb).
6.1.1 The speed of forming shall be between 4.8 and 25
mm/min (0.2 and 1.0 in./min). The speed is usually slowed to
measure more accurately the final height as shown on the dial
indicator, but the final punch speed shall be controlled at 6 mm
(0.24 in.) per min maximum.
6.2 Indenting Ball, with a diameter of 41 mm (1.625 in.), a
Rockwell hardness number not less than 61 on the Rockwell C
scale (HRC), and a smooth surface finish not exceeding 4 µm
(160 µin.). The indenting ball shall not deform during the test.
Theballandholdershallmovethroughthecenterlineofthetop
and bottom dies. The ball shall be clean and free of oil, grease,
oxide buildup, rust, dirt, nicks, or other damage.
6.3 Ball Holder, to hold the ball in its seat during the test.
Most ball holders are removable so that other ball punch
deformation tests can be done in the same machine.
6.4 Upper and Lower Dies, with a hardness of 56 HRC or
higher. The upper die shall have an approach radius of 1.6 6
0.05 mm (0.0625 6 0.002 in.) for steel thicknesses less than
1.50 mm (0.059 in.) and an approach radius of 4.8 6 0.15 mm
Draw distance = 0.512 in. (13 mm)
Ball diameter = 1.625 in. (41 mm)
(0.1875 60.006in.)forsteelthicknessesgreaterthan1.52mm
FIG. 1 Survey of Strain Over Biaxially Stretched Dome
(0.060 in.).The diameter of the opening in the upper and lower
die shall be 42 mm (1.64 in.). In most machines, these dies are
removable.
5.3 It should be recognized that variability in the results
6.5 Dial Indicator,ridingonthesurfaceoftheformingsheet
persists due to the test conditions and forming machine to monitor the movement of the penetrator (ball) and graduated
variations.
so that the displacement, or ball height, can be measured at
least to 6 60 mm (0.0025 in.) but preferably to 6 25 mm
6. Apparatus and Materials (see Fig. 2)
(0.001 in.).
6.1 Forming Machine, equipped with a spherical-ended
6.6 Adhesive Tape, 25 mm (1 in.) wide, transparent, high-
penetrator to deform th
...

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: D7093 − 13 D7093 − 19
Standard Test Method for
Formability of Thin Film Organic Coatings on Steel Over a
Biaxially Stretched Dome
This standard is issued under the fixed designation D7093; 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 test method covers the evaluation of the formability and adhesion of factory applied thin film organic coatings on steel
with having coating thicknesses of 2.5 to 10 microns (0.10 to 0.40 mils) typical of those used in the coil coating industry.
1.2 The degree of oil removal prior to forming, the techniques of taping, and differences in adhesive strength of the tape can
affect the adhesion rating.
1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.4 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 a specific hazard statement, see Section 7.
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:
D3330/D3330M Test Method for Peel Adhesion of Pressure-Sensitive Tape
2.2 Other Document:
Pictorial Standards of Coating Defects
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 dome height, n—the height of the dome formed in the test.
3.1.2 indenting ball diameter, n—the diameter of the spherical-ended penetrator (ball) used to deform the specimen.
3.1.2.1 Discussion—
The 41 mm (1(1.625 ⁄8 in.) diameter ball was selected because it minimizes the variability in the localized peak strain. This size
ball is commercially available and is as large as most testing machines can accommodate.
3.1.3 percent strain, n—the percent elongation of scribed gagegauge lengths after forming.
3.1.3.1 Discussion—
This test method is under the jurisdiction of ASTM Committee D01 on Paint and Related Coatings, Materials, and Applications and is the direct responsibility of
Subcommittee D01.53 on Coil Coated Metal.
Current edition approved June 1, 2013May 1, 2019. Published July 2013June 2019. Originally approved in 2004. Last previous edition approved in 20042013 as D7093
– 04 which was withdrawn January 2013 and reinstated in June 2013. DOI: 10.1520/D7093-13.13. DOI: 10.1520/D7093-19.
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.
Copies of the pictorial photographic reference standard are contained in the publication Pictorial Standards of Coatings Defects and may be obtained from the Federation
of Societies for Coatings Technology, 492 Norristown Rd., Blue Bell, PA 19422. The silver halide gelatin photographs are intended to be the only primary reference standards
for this test method. The reproductions of them in this test method are for the purpose of illustration only.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7093 − 19
For the draw height of 13 mm (0.512 in.), using a 41 mm diameter ball, the localized peak strain is about 19 % (see Fig. 1).
4. Summary of Test Method
4.1 A coated specimen is biaxially stretched a given distance in an appropriate machine, adhesive tape is applied to the deformed
area (dome) and then pulled off, and the amount of coating removed is compared with a photographic standard to determine the
coating adhesion rating.
5. Significance and Use
5.1 The results of the combined deformation and tape test are related to the ability of the coated metal to withstand stamping
in factory applications.
5.2 This test can be used to determine or control the manufacturing process or in for coatings development work to improve
the product.
5.3 It should be recognized that variability in the results persistpersists due to the test conditions and forming machine
variations.
6. Apparatus and Materials (see Fig. 2)
6.1 Forming Machine, equipped with a spherical-ended penetrator to deform the specimen with appropriate dies, until the
required height is obtained, and clamping arrangement to hold the specimen with a minimum pressure of 8.9 kN (2000 lb).
6.1.1 The speed of forming shall be between 4.8 and 25 mm/min (0.2 and 1.0 in./min). The speed is usually slowed to measure
more accurately the final height as shown on the dial indicator, but the final punch speed shall be controlled at 6 mm (0.24 in.)
per min maximum.
6.2 Indenting Ball, with a diameter of 41 mm (1(1.625 ⁄8 in.), a Rockwell hardness number not less than 61 on the Rockwell
C scale (HRC), and a smooth surface finish not exceeding 4 μm (160 μin.). The indenting ball shall not deform during the test.
The ball and holder shall move through the centerline of the top and bottom dies. The ball shall be clean and free of oil, grease,
oxide buildup, rust, dirt, nicks, or other damage.
6.3 Ball Holder, to hold the ball in its seat during the test. Most ball holders are removable so that other ball punch deformation
tests can be done in the same machine.
6.4 Upper and Lower Dies, with a hardness of 56 HRC or higher. The upper die shall have an approach radius of 1.6 6 0.05
mm (0.0625 6 0.002 in.) for steel thicknesses less than 1.50 mm (0.059 in.) and an approach radius of 4.8 6 0.15 mm (0.1875
Draw distance = 0.512 in. (13 mm)
Ball diameter = 11.625 ⁄8 in. (41 mm)
FIG. 1 Survey of Strain Over Biaxially Stretched Dome
D7093 − 19
Dimensions
Key
Inch-Pound Metric
1 Test specimen — —
2 Spherical-ended penetra- 1 ⁄8 in. 41 mm
tor (ball)
3 Ball holder — —
4 Clamp force (minimum) 2000 lbf 8.9 kN
5 Upper die; bore diameter 1.64 in. 42 mm
6 Lower die; bore diameter 1.64 in. 42 mm
7 Dome height 0.512 in. 13 mm
8 Upper die corner radius 0.0625 in. 1.6 mm
FIG. 2 Tooling for F
...