Reamer is mostly used to finish existing holes. When holes are created using common applications such as drilling or punching, these holes are often left with some minor imperfections or inaccuracies. Their roundness may be flawed, or their inner diameters may be slightly smaller than required.Here comes the use of Reamers. A Reamer is a part of machine tools. A Reamer is a rotary cutting tool which we used for finishing the hole after drilling or boring. The process of finished the hole internally is called reaming. A Reamer is always worked in clockwise direction
Now we discuss some design features & element of Reamers. A Reamer has straight & parallel cutting edges. Reamer has very sharp edges & hard material. Its little bit looking like a drill bit but the geometry of this tool is totally different. The reamer is used for remove the small metal chips inside the hole or bore. Shanks on Reamers also have some different types.
1) Straight shank
2) Straight round shank
The main difference between drill and Reamer is diameter. A drill makes a hole inside the work piece roughly but a reamer is concert into a finished & fine hole. It also provides smoothness inside the hole.
Now we discuss some types of Reamers.
1) Hand Reamer: - It is a simple type of Reamer that we use for small part work. It is a straight shank type Reamer. It’s also working on small holes, light metal, soft materials, wood, plastics etc.
2) Machine Reamer: - A machine Reamer has very slight, sharp edges. The work piece is set in a vice and reamer operation is applied by machine. There is no risk during this operation. It’s totally safe by the point of view of safety.
3) Taper Reamer:- This type of Reamer we used for to make a taper hole inside the job. There is a taper pin which is working as self tightening devise due to shallow angle as like jigs. The main use of this Reamer is in air craft industry. It also holds in machine such like a drill and working smoothly. We also called it finishing Reamer.
4) Combination Reamer: - It is also a type of Reamer. It has two or more cut surfaces. It always used on a CNC machine. This reamer is hold by magazine of CNC machine. There is a particular coding set for this in computer. They are called G- codes. The material of this Reamer is carbide and cobalt. The cost of this reamer is very high. They also need an extra care because of high brittleness.
Selection of a Reamer:- The selection of a reamer is totally depend on our work, our skills, our experience. It’s also depending on reamer materials, reamer design, room temperature, speed of machine & operator skills. The work done by reamer is fine or not it’s totally depending on methods of operations. To success the operation we also need some better conditions on machine table for example proper supply of coolant, better machine conditions. There is always a standard method of reaming process. Reaming is done on drill press, machine centre etc.
Materials of Reamer:- The reamer materials is also like end mills & drills materials. I mean high speed steel, tungsten carbide. The most common materials of reamer are high speed steel. Because of sharp cutting edges & large cutting force its works very well. 2nd most common material is tungsten carbide. It’s really very hard as compare to high speed steel. It used for reaming on very hard materials. Aluminium and brass have very good machining properties.
Warning:- During the reaming operation a reamer is contact with work piece and produced a very high temperature . because of this high temperature a tool may be melt or blunt. So there is a proper coolant supply we need during operation. Our coolant is soluble oil, mineral oil, diesel, water etc.