5.1 This test method can be used to predict the comparative lubricating properties of a metalworking fluid (MWF).

5.1.1 Fluids that produce lower torques or higher efficiencies are predicted to have better machining characteristics.

5.2 The method is applicable to all tap types, machining speeds, alloys and coatings that can be fabricated into a test piece.

5.3 Comparison between different operating conditions or various types of fluids can be made.

5.4 The reportable quantity is the efficiency or mean average torque of a reference fluid divided by the mean average torque of the fluid of interest.

1.1 This test method describes a laboratory technique to evaluate the mean lubricant efficiency of metal removal fluids using an instrumented tapping machine that measures and records torque.

1.1.1 The method is applicable to all tap types, machining speeds, and alloys that can be fabricated into a test piece. Comparison can be made between different operating conditions or various types of fluids including straight and emulsifiable oils, semi-synthetics and synthetic fluids (see Classification D2881).

1.1.2 Repeatability and reproducibility mean lubricant efficiency from an interlaboratory study using aluminum 6061-T6 test substrates and commercial metalworking fluids (MWF) are shown in Section 16.

1.1.3 Test method precision is affected by MWF formulation, tap and alloy tested. Recognizing that there are thousands of alloys and innumerable MWF formulations, the precision statistics provided in Section 16 might not apply to MWF formulations, taps, and alloy combinations not included in the interlaboratory study. Users are advised to determine repeatability precision for the specific MWF formulations and alloys they use when performing this test method.

1.2 The values stated in SI units are to be regarded as standard.

1.2.1 Exception—The units for the threads of the tap, M6, are in metric thread units.

1.3 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.

1.4 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.