ASTM C285-10(2020)

1.1 These test methods cover the determination of the fineness of frit in wet- or dry-milled porcelain enamels and other ceramic coatings for metals by means of the No. 200 (75-µm) or No. 325 (45-µm) sieve.

1.2 The two methods appear as follows:

1.3 Method A is intended for use where a referee method of higher accuracy is required, while Method B is intended to meet the needs of normal enamel plant production control operations where a rapid, simplified method of sieve testing is required. The accuracy of the simplified method has proved to be entirely adequate for this use. The simplified test, however, is not recommended where high accuracy is required.

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.

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.

3.1 The fineness of the frit has a direct bearing on many of its properties, such as fusibility, tearing, gloss, opacity, suspension in the slip, and ease of spraying.