Sturdy and Durable - Mading from high carbon hardened steel, precision second-cut grade, clear teeth. Rockwell Hardness: 60 HRC, File pattern type: Single grain. Polishing area: approx 90mm.Simple, functional and well-built - From Rough-Shaping Wood To Sharpening Blades, The ANDGOO 4-Way Shoe Rasp File Is A Combination Of Four Tools In One To Handle A Wide Variety Of Work, 4 in 1 Wood Rasp: Flat Mill, Half-round Second-cut, Flat Wood Rasp, Half-round Wood Rasp. Reliable and Efficient - The Flat Mill File Smooths Edges And Sharpens Blades. A Half-Round Second-Cut File Smooths The Inside Surfaces Of Contoured Openings And Holes. The Flat Wood Rasp Rough-Finishes Wood, Leather, Soft Metals, And Soft Plastics. A Half-Round Wood Rasp Roughly Shapes The Interior Contours Of Wood, Leather, Soft Metals, And Soft Plastics.