What is the best lubricant to prevent wear and increase cutting efficiency for tapping common steels?

The choice of sulfur-based oil as the best lubricant for tapping common steels is based on its properties that effectively reduce friction and wear during the machining process. Sulfur-based oils contain additives that form a protective film on the cutting tool and workpiece surface, significantly enhancing cutting efficiency. These additives help to dissipate heat generated during the tapping operation and also help in minimizing tool wear, which is especially crucial when working with tougher materials like steel.

In comparison, other options have different characteristics that make them less suitable for this specific application. Water-based lubricants may evaporate quickly and lack the necessary viscosity to provide adequate lubrication under high-pressure conditions. Vegetable oils can offer some lubrication but might not withstand high temperatures and loads as effectively as sulfur-based oils. Silicone spray, while useful for various applications, generally does not provide the level of protection and cooling needed during metal cutting processes, making it less effective for tapping operations.

Therefore, sulfur-based oil is recognized for its performance in reducing wear and enhancing cutting efficiency when working with common steels.