Diamond coating in length 110 mm. Grain size D126. HB files from Strauss & Co. they are produced in sizes suitable for heavy loads and are used for filing large areas of various metal materials, plastics, fiberglass, graphite and epoxy resins. Not only does it successfully handle machining under heavy loads, but the service life of the files is also very long. HB files have a square handle suitable for fixing in the handle.