3.1 This test method is intended to evaluate filaments for suitability of use in paintbrushes prior to manufacture. Filament fracture resistance is very important because paintbrushes are bent or flexed during painting and it is necessary that the filaments are not permanently deformed with usage.

1.1 This test method covers a procedure for determining the number of fractures present when paintbrush filaments are bent.

1.2 This method is applicable only to monofilaments with consistent longitudinal cross sectional dimensions commonly referred to as “level” filaments.

1.3 The values derived are in percent fractured filaments. For example, 2 fractured out of 18 filaments tested = ²/₁₈ or 11 %.

1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.

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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

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.