铰刀，你可以放大钻孔等，或缩小形状的工具。有粗加工、精​​加工根据不同的应用，是一种螺旋形，如钻头的刀片的直线形状。虽然适合在广泛的范围内的孔的大小，孔也可以是圆锥形。

可调节手用铰刀，是靠调整节两边的螺母,使刀片沿本体上的斜底槽移动，以改变铰刀的直径尺寸。

A reamer is a type of rotary cutting tool used in metalworking. Precision reamers are designed to enlarge the size of a previously formed hole by a small amount but with a high degree of accuracy to leave smooth sides. There are also non-precision reamers which are used for more basic enlargement of holes or for removing burrs. The process of enlarging the hole is called reaming. There are many different types of reamer and they may be designed for use as a hand tool or in a machine tool, such as a milling machine or drill press.