Meaning and Purpose
3.1 For more than half a century, the Sward type hardness rocker instruments have been used by the coating industry as NDE instruments to measure the cured and final surface hardness of organic coatings (see References). (1) through (2)). This test method can be used in the laboratory to quickly screen and measure the surface hardness of candidate coatings.

Note 1: In a previous task group aimed at establishing an ASTM method for measuring the hardness of organic coatings using a Sward type hardness rocker arm instrument, cyclic test results consistently showed poor inter-laboratory reproducibility. The lack of inter-laboratory agreement may be caused by dimensional differences between instruments, and in this regard contact with the rocker arm ring is a very likely violator. Several manufacturers of the Sward type hardness rocker produce instruments that vary in net weight and ring radius. Some of them exceed the measured values and net weights required in this test method.

ASTM D 2134-93-2019 Determination of Hardness of Organic Coatings with a Swalt-type Hardness Tester

Scope of
1.1 The test method covers the determination of the relative degree of surface hardness of organic coatings using specific equipment used in the coating industry.

1.2 Values expressed in SI units shall be regarded as standards. The values given in parentheses are for reference only.

1.3 This test method is not intended to address all safety issues, 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 to determine the applicability of regulatory restrictions prior to use.

1.4 This international Standard has been developed in accordance with the internationally recognized standardization principles established in the Decision on Principles for the Development of International Standards, Guidelines and Recommendations issued by the Committee on Technical Barriers to Trade of the World Trade Organization.