Carborundum Hones

 Carborundum Sharpening Stones

The word Carborundum is often used to describe most any manmade oilstone; when in fact, the word Carborundum is quite specific.

Carborundum was the name given to silicon carbide by Edward Goodrich Acheson. In 1890, Acheson was attempting to recreate diamonds. In doing so, Acheson experimented with carbon by mixing it with clay and electrically fusing it. The result was a product extremely hard and abrasive. The product was silicon carbide. Acheson named the silicon carbide product, “Carborundum’ and obtained a patent on it.

Edward Goodrich Acheson formed a company in  Monongehela, PA and named it Carborundum. Abrasives were made from this new material, silicon carbide (Carborundum), in many shapes and sizes. In 1895 Acheson moves his company to Niagara Fall, N.Y...

Carborundum Corporation started producing sharpening stones in various grits and sizes. Many of the stones were dual grit, meaning a rough side of larger grit silicon carbide and a smoother side of smaller grit silicon carbide. Carborundum Corporation also produced stones with a finer grit that was used to sharpen razors.

Carborundum sharpening stones were given numerical grit rating from approximately 120 to 1200; 120 being a larger, rougher grit size and 1200 being a smaller, smoother grit size

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Finding a company document that assigns a grit rating for Carborundum stones, over 1200 grit, is difficult. There are Carborundum stones designated as razor hones in the approximate 4000 grit rating. This is usually determined by comparing a Carborundum razor hone, to an established high grit water stone by a company such as Norton. 

 The Carborundum Company made a number of razor hones, though not all Carborundum hones are suitable for razors. This is a partial list of the product numbers; 45,79, 101, 101A ,102, 103, 103A, 103C, 103G, 104, 105, 106 - soft and porous,112 ?,115S, 118S, 124 - soft and porous, 152, 159, 180, 201 4" x 1 7/8" (not 6"x2 1/2")
Carborundum closed its Niagara Falls bonded abrasives plant in 1983.

 
Here are some links to discussions on Carborundum stones:

Un-numbered Carborundums

 

Below are photos of Carborundum (silicon carbide) sharpening stones; along with other types of abrasive sharpening stones that are often considered Carborundun, but are a different material product.