A hollow drill is a mechanical device that utilizes hollowed out, cylindrical drill bits and is used for the purpose of drilling holes through various objects and surfaces. These drill bits can be made from different kinds of strong metal and are available in a wide array of shapes and sizes. Hollow drills are used in many industries and for a variety of purposes.
One of the most common types of hollow drill is a paper drill that is made to “punch” holes through stacks of paper. Typical drill bits are bad to use for this application simply because paper is delicate and they tear through it rather than drilling fine holes. The hollow drill bits used in a paper drill are smooth, hollow and cylindrical with a razor-sharp edge for cutting through the paper. These allow the paper that has been extracted from the holes to be easily removed through the hole in the drill bit rather than creating a lot of paper dust. Any number of hollow drill bits, typically ranging from one to six, but possibly more, can be arranged in a row on a hydraulic hollow drill press.
The items that need holes punched through them, which can be a stack of paper or cardboard, are then placed in their desired position beneath the bits. The machine operator will then safely engage the machine to bring the rotating drill bits down and through the objects. Once they are all the way through, the bits return to their upright position along with the paper that has been extracted from the holes. As the process is repeated, the waste paper is pushed up through the drill bits and out of the machine into a waste receptacle. Usually a substance like wax must be applied to the drill bit when it is in use to keep it from overheating due to friction.
On the opposite end of the spectrum, hollow drills can also be utilized to cut holes into hard and dense materials like rocks. In this case, the hole in the drill bit exists for the purpose of pumping liquid, such as water, while drilling in order to preserve the integrity of the hollow drill bit until the desired depth is reached. The purpose of this is typically for creating blast holes for blowing up rocks that need to be removed from a large area, but there can be many reasons for drilling holes through dense materials.
For science, a hollow drill rod may be used to extract sample material from the ground for study. The drill is dug into the ground or ice, for instance, and when it is extracted, a scientist can save the sample to be studied. This is mainly used when studying the effects of an area over time, since the sample will represent how the composition of the dirt has changed, possibly even over millions of years.
