The Free Dictionary defines milling as the act or process of grinding. A metal lathe is used to cut or grind down metal and create symmetrical shapes. Metal lathes spin a block of metal on its axis at variable speeds. Cutting or abrasive tools are applied to the spinning piece of metal, shaping it by removing metal.
Different metal lathes are used for different applications. The five basic types are turret lathes, mini lathes, engine lathes, CNC lathes and capstan lathes. Engine lathes and mini lathes are primarily used to create custom metal parts. Turret lathes and capstan lathes are most commonly used in applications that involve the mass production of materials.
A metal lathe’s carriage houses a saddle, cross slide, top slide and an apron. Other vital components of a metal lathe include a headstock, bed, headstock spindle, lead screw, back gear, countershaft, tailstock, tumble reverse and change wheel.
The bed is the foundation of a metal lathe that holds all the components together. The saddle slides along the top of the bed and the apron, which is attached to the front of the saddle, carries gears. Headstocks allow the spindle, which holds the workload, to rotate at adjustable speeds. Back gears increase torque and countershafts reduce spindle speeds. The tailstock is adjustable and can be locked at any point along the bed to hold the opposite end of the workload.
Metal lathes can be very dangerous. You should not wear loose-fitting clothing around the moving parts. Wear goggles to prevent injury from flying debris.