<P> Honing oil is a liquid, solution or emulsion used to aid in the cutting or grinding of metal, typically by abrasive tools or stones, and may or may not contain oil . It can also be called machining oil, tool oil, cutting fluid, and cutting oil . </P> <P> In the context of hand blade sharpening, honing oil is used on a sharpening stone to protect the stone, carry away the debris (swarf), and to more efficiently produce a keen edge on a metal blade such as a knife . In a machine shop it also carries away excess heat and depending on composition, may prevent unintentional tearing and welding of the metal . Or when used with materials such as soft copper, it may have extra additives to prevent stone loading, or metal deactivators to prevent staining of copper containing alloys . To achieve maximum cutting rates and abrasive life with petroleum (mineral) based machining oils when honing difficult materials like stainless steel, a higher level of surface active lubricity agents are combined with sulfur extreme pressure additives . Industrial honing oil is typically available in: 5 gal pails, 55 gal drums, 275 gal and 330 gal totes, while home knife honing oils are typically available in 1 oz, 4 oz, and 12 oz . bottles . </P> <P> There are many different kinds of "honing oils" to suit different needs . It is important to use the appropriate solution for the job . In the case of knife sharpening, motor oil is too thick or "heavy" and can over-lubricate or clog a sharpening stone, whereas WD - 40 is too "light" an oil and will not carry the metal filings plus stone dust (collectively known as "swarf") away from the stone, and clog it . Not using any oil at all will also clog or "glaze" the stone, again reducing its cutting power . Historically sperm whale oil, Neatsfoot oil, and other animal fats were popular . </P>

What type of oil to use for sharpening stone