slipstone

Slipstone, also called slip stone, is a small abrasive stone historically used to sharpen and finish metal edges. Before the advent of modern whetstones, slipstones provided a portable, hand-held means of refining blades, tools, and edging surfaces. They are typically flat or slightly tapered and made from fine-grained stones such as sandstone, quartzite, or chert; some modern versions are synthetic for consistent hardness.

The stones are used by rubbing or drawing the blade edge across the stone at a controlled angle. Light pressure is applied, and water or oil may be used to wash away abrading particles and reduce heat. Repeated passes remove burrs and refine the bevel, producing a keener edge. Slips were valued for suitability with small or delicate workpieces where larger sharpening stones were impractical.

Historically, slipstones have been found in toolkits and workshops across various cultures, associated with blacksmiths, swordsmiths, woodworkers, and craftsmen who required precise edge work on relatively small blades and tools. Today, slipstones are primarily of historical interest or collected as antique tools, though the term may appear in older manuals and catalogs describing traditional sharpening practice. Modern abrasive sticks and stones have largely supplanted traditional slipstones, but the basic technique remains a foundational concept in edge maintenance. See also: whetstone, sharpening stone, edge refinement.