Chisel, hammer, file and abrasive paper

A file is a cutting tool: a bar or block of various sizes and shapes with teeth cut into its working surface. Files are made flat, square, triangular and round. Their teeth are wedge-shaped ridges formed between grooves. Files differ by tooth size and by the number of teeth per 10 mm of working length: coarse files have 5–12 teeth and are for rough work. A file is made of tool steel. With a file a small allowance is removed from a blank so the part reaches the exact size and shape on the drawing. A file is moved back and forth: the forward movement is the working stroke (the file is pressed) and the backward movement is the idle stroke (not pressed). A file is not used without a handle; the handle must sit tightly on the tang, because the tang is sharp and can pierce the hand. During filing the blank is clamped firmly in the vice; fine filings are cleared with a brush, not by hand.