Which of the following is NOT a characteristic of good cutting fluids?

High viscosity is typically not considered a characteristic of good cutting fluids because it can hinder the fluid's ability to effectively flow into the cutting zone. Good cutting fluids are designed to adequately cool the cutting tool and the workpiece, while also providing lubrication to reduce friction and wear.

Cooling properties ensure that the temperature at the cutting interface is kept low, preventing thermal damage to both the tool and the material being machined. Lubrication capabilities help in minimizing direct contact between the tool and workpiece, thus reducing wear and extending tool life. Corrosion resistance is also crucial, as it protects both the cutting tool and the machine components from rust and degradation caused by the fluid or machining process.

In contrast, high viscosity can lead to difficulties in pumpability and application, making it less effective in fulfilling the intended roles of cooling and lubrication. This is why high viscosity is identified as not being a characteristic of good cutting fluids.