Angle or Tangent hand file FINE. Excellent anywhere there is a 90° angle needed. The R-201 is approximately 75°, which gives the builder the accuracy needed to shape a 90° angle. Either an 1/8th radius or a sharp corner can be produced simply by rotating the tool. Model builders find this particularly useful for fabricating servo trays, it is also good for cleaning corners and edges on laser cut wood. Very popular and a good starting point if this is your first Perma Grit hand tool purchase. COARSE approximately to equivalent UK 320 / USA 120 sandpaper. Perma-Grit® Tools will cut:- All Woods, Glass Fibre, Carbon Fibre, Kevlar, Plexiglas, Lexan, Perspex, Acrylics, Plastics, Polystyrene, Brass, Copper, Aluminium, Ceramics, Stone, Horn, Antler etc.