GB/T 45973-2025Paints and varnishes - Scratch test using a spring-loaded pen (English PDF)

Foreword

This document was drafted in accordance with the rules provided in GB/T 1.1-2020 Directives

for Standardization - Part 1.Rules for the Structure and Drafting of Standardizing Documents.

This document identically adopts ISO 22557.2019 Paints and Varnishes - Scratch Test Using a

Spring-loaded Pen.

The following minimal editorial change is made to this document.

---Additional information on corresponding scratch types is added to 7.6.

Please be noted that certain content of this document may involve patents. The institution

issuing this document does not undertake the responsibility of identifying these patents.

This document was proposed by China Petroleum and Chemical Industry Federation.

This document shall be under the jurisdiction of National Technical Committee 5 on Paint

Pigment of Standardization Administration of China (SAC/TC 5).

The drafting organizations of this document. Yejian New Material Co., Ltd.; Changzhou

Guanghui New Materials Research Institute Co., Ltd.; Guohengxin (Changzhou) Testing and

Certification Technology Co., Ltd.; Biuged Precision Instruments (Guangzhou) Co., Ltd.;

Fujian Wanan Group Co., Ltd.; Fujian University of Technology Geotechnical Engineering

Research Institute Co., Ltd.; CNOOC Changzhou Paint and Coatings Industry Research

Institute; Beijing Aerospace Xinli Technology Co., Ltd.; Guangdong Nippon Changrunfa

Technology Materials Co., Ltd.; Shanghai Customs Industrial Products and Raw Materials

Testing Technology Center; Minjiang University.

1 Scope

This document describes a method for determining the scratch resistance of coatings by

inducing scratches using a commonly used handheld, loaded stylus.

Either point stylus (Method A) or disc stylus (Method B) can be used for the test.

Both methods are universally applicable and can be used in the field as well as on curved

surfaces. Method A can also be used for small specimens (minimum size 30 mm × 50 mm).

This test can be performed as a "pass/fail" test (Test Requirement I) or as a grading test (Test

Requirement II).

2 Normative References

The contents of the following documents constitute indispensable clauses of this document

through the normative references in the text. In terms of references with a specified date, only

versions with a specified date are applicable to this document. In terms of references without a

specified date, the latest version (including all the modifications) is applicable to this document.

ISO 868 Plastics and Ebonite - Determination of Indentation Hardness by Means of a

Durometer (Shore hardness)

NOTE. GB/T 2411-2008 Plastics and Ebonite - Determination of Indentation Hardness by Means

of a Durometer (shore hardness) (ISO 868.2003, IDT)

ISO 2808 Paints and Varnishes - Determination of Film Thickness

NOTE. GB/T 13452.2-2008 Paints and Varnishes - Determination of Film Thickness (ISO

2808.2007, IDT)

ISO 4618 Paints and Varnishes - Terms and Definitions

NOTE. GB/T 5206-2015 Paints and Varnishes - Terms and Definitions (ISO 4618.2014, IDT)

ISO 13076 Paints and Varnishes - Lighting and Procedure for Visual Assessments of Coatings

NOTE. GB/T 37356-2019 Paints and Varnishes - Lighting and Procedure for Visual Assessments

of Coatings (ISO 13706.2012, IDT)

ISO 14526-1 Plastics - Phenolic Powder Molding Compounds (PF-PMCs) - Part 1.Designation

System and Basis for Specifications

NOTE. GB/T 1404.1-2008 Plastics - Phenolic Powder Molding Compounds - Part 1.Designation

System and Basis for Specifications (ISO 14526-1.1999, IDT)

CEN/TS 13388 Copper and Copper Alloys - Compendium of Compositions and Products

EN 10027-2 Designation Systems for Steels - Part 2.Numerical System

3 Terms and Definitions

The terms and definitions defined in ISO 4618 and the following are applicable to this document.

ISO and IEC maintain terminology databases for standardization at the following addresses.

4 Principle

Manually move a stylus with a test load between 0.5 N and 20 N on the coating surface and

visually inspect (using a magnifying glass) and assess the resulting damage.

The test can be performed using a point stylus (0.50 mm, 0.75 mm or 1.00 mm in diameter) in

accordance with Method A or using a disc stylus [made of stainless steel, copper, thermosetting

materials, or PMMA (polymethyl methacrylate)] in accordance with Method B.

5 Instruments