The Difference Between Blanchard Grinding and Precision Grinding


Grinding is a machining process that uses an abrasive to bring a material to its desired dimensions and surface finish. There are many different types of grinding available, and in this blog we will look at the differences between Blanchard Grinding and Precision Grinding. Blanchard grinding is used on materials with a large surface area to remove stock from one side, whereas precision grinding is used to achieve a superior surface finish, high degree of parallelism or flatness on materials with small surfaces.

What is Blanchard Grinding?

Blanchard Grinding

Blanchard grinding is used to efficiently remove stock from one side of material with a large surface area. Blanchard grinding, also known as Rotary Surface Grinding, was developed by the Blanchard Machine Company in the 1900s. It is a far more economical process than precision grinding. As a result, Blanchard grinding is best suited for large pieces of material, and is typically not used to grind anything to a tolerance of less than 0.001”. It can leave a surface finish around 65 RMS and also leaves a signature grinding mark that some consider to have aesthetic appeal.

For large ferrous materials, magnets are usually used to hold the material in place while the grinding occurs. Blanchard grinding can work well on a variety of non-ferrous materials, however, alternative types of holding devices must be used.

Blanchard grinding is typically used on:

  • Large castings and forgings
  • Large sections of plate stock
  • Large stampings
  • Molds and dies

What is Precision Grinding?

Precision grinding is used for materials with relatively small surfaces that require a high degree of flatness, a high degree of parallelism, or a superior surface finish. It is used for applications for requiring tolerances of up to +/- 0.0001” and can achieve surface finishes of around 10 RMS. It is typically used as the one of final machining processes on a part.

There are several different types of precision grinding:

  • Horizontal Spindle Surface Grinding: This method employs an abrasive wheel that is rotated at high speeds and then brought into contact with a flat surface of a part.
  • Cylindrical grinding: This process is very similar to horizontal spindle surface grinding except it is used to grind round objects and therefore requires a different work holding device. The abrasives used in cylindrical grinding can be dressed in such a way that helps to shape the part.

Some common abrasives for both horizontal spindle surface grinding and cylindrical grinding include aluminum oxide, zirconia alumina, and silicon carbide. Depending on the application, lubricants may be used to keep the high temperatures caused by the grinding process down.

Other types of precision grinding processes include centerless grinding, internal diameter grinding, and creep-feed grinding. Typical applications include:

  • Molds and dies
  • Stampings
  • Shafts
  • Bushings
  • Machine components
  • Pistons
  • Cylinders

Metal Supermarkets

Metal Supermarkets is the world’s largest small-quantity metal supplier with over 100 brick-and-mortar stores across the US, Canada, and United Kingdom. We are metal experts and have been providing quality customer service and products since 1985.

At Metal Supermarkets, we supply a wide range of metals for a variety of applications. Our stock includes: mild steel, stainless steel, aluminum, tool steel, alloy steel, brass, bronze and copper.

We stock a wide range of shapes including: bars, tubes, sheets, plates and more. And we can cut metal to your exact specifications.

Visit one of our 100+ locations across North America today.

Related blog articles

Shopping from the UK?

Visit our UK website for our stores, online ordering and product availability.