A bench drilling machine is more commonly found in a machine shop than in someone's garage or casual work shop. These machines are large and stationary, often the height of the user if not taller. They require a power source and can sport a variety of different bits to drill a number of different holes. With the proper bits, a bench drilling machine serves a wide variety of uses.
The basic function of a bench drilling machine is to drill holes in wood, metal and a variety of other materials provided the machine has enough power and the proper drill bits. For instance, a wood drilling bit is made of different materials and is shaped differently from a metal or concrete drilling bit. Although drilling is the most common task for these machines, it is by no means the only task they can perform.
With the proper set-up, a bench drilling machine can be altered so that it becomes a boring machine. A boring bit is much larger than a drill bit, although it serves essentially the same function. Rather than drilling a small hole that will be filled by a screw or nail (a pilot hole), a boring bit creates a large hole that may not be meant to be filled. Much like a tunnel boring machine, a boring bit merely carves out part of the material for a construction purpose. To turn a bench drilling machine into a boring machine, you simply have to switch the bit.
For mechanical buffing, a bit can be put on the end of a bench drilling machine to turn it into a buffing machine. The downward force you can get with a bench drilling machine saves a lot of heavy muscle work that would be spent trying to buff a particularly resistant piece of metal by hand. Portable buffer bits can be put into a hand drill, but those will still require a lot more force from the worker than a similar bit used in a bench drilling machine.