Lathe cutters are machines that hold a rotating object that requires cutting, along the outer surface, or reaming. Used since Greco-Roman times, lathe cutters now generally contain motorized parts that provide the rotation and may automatically move the cutter along the surface. Types of lathes vary from palm-sized jewelry cutters to massive, room-sized machines used to create crankshafts and camshafts. Metal, plastic, and wood are common materials that are formed on a lathe cutter.
The size of a lathe is usually expressed numerically. For example, a common type of lathe might be defined as 10 inches x 36 inches (25.4 cm x 91.44 cm). The first number is the swing size, or the distance from the lathe bed to the mounting spindle. This measurement means that the machine holds material up to 5 inches (12.7 cm) in diameter, or half the swing size. The second number is the distance from one mounting point to another, or the maximum allowable length of the material.
Manufacturers generally produce lathe cutters in three categories, referred to as engine, precision, and gap lathes. An engine lathe is generally lightweight, fits on a workbench, and is capable of handling materials up to 10 inches (25.4 cm) in diameter. Precision, or tool room, lathes may be tabletop or floor standing models and are often used in tool and die shops. Some of these lathes can hold materials up to 25 inches (63.5 cm) in diameter and 200 inches (508 cm) in length. Gap lathes perform functions that are similar to those of precision lathes but have extendable beds, capable of handling extremely large pieces of material.
Metal and wood lathes can have either a horizontal or vertical bed, which may contain the motor. On one end of the bed, lies the headstock, containing bearings and a rotating spindle. The spindle holds one end of the material. On the other end of the bed is the tailstock, which holds the other end. Tailstock lathe parts usually slide back and forth along the bed to accommodate varying lengths of material.
Metalworking lathe cutters often have a carriage mounted on the bed between the headstock and the tailstock with a cross slide sitting atop this saddle/apron mount. On top of the slide is a rest that holds the cutting tools. This tool post may have the capacity for both linear and rotary movement. The tools themselves generally lie in slots on the post, which rotates into the material at the desired angle and depth.
Woodworking lathes do not have a cross slide. Instead, these lathe cutters have a mounted work piece with a tool rest. This device generally lies along the length of the material and provides a resting place for the handheld tools that are commonly used in woodworking. Lathe accessories generally include different types of spindle mounts along with the specific cutting tool bits or chisels required.