High precision reaming starts with a perfect reamer
Reamers play such an integral role in today's machine shop and are so vital to a machinist's tool arsenal that the saying is widely circulated that if you want a precise hole, start with a perfect reamer.
In a high-quality machine shop, if an operator needs to drill a precision hole, chances are he or she will need to use a reamer to get it done.
What is a reamer and why is it so important?
There are many types of reamers, including tapered pins and hand reamers. The following refers to high-precision mechanical reamers that use lubricant in the heart of the lathe or process. Regardless of the application, a reamer is a precision tool. Its successful manufacture depends not only on the grinder and operator, but also on the characteristics of the tool itself. Reamers can be produced in carbide, HSS or metal-ceramic composites.
Reaming is, essentially, the process of reaming a hole. The reamer is designed to ream the hole size to a small degree, but with a high degree of precision, ensuring a smooth surface finish on the sides of the hole. Properly used, reamers can ream thousands of holes to high precision holes without degrading performance.
Reamers are the most accurate holemaking tools available, and if used in metalworking they are typically used to high precision tolerances of H6 / H7 according to ISO standards. both ISO and ANSI metric standards they refer to fasteners that can be freely assembled and disassembled.
Reamers do not remove large amounts of material. The amount of material removed depends on several factors, including the material to be machined and the size and quality of the pre-drilled hole. For the machinist, this is a process that requires a careful balance. In order for the reamer to work efficiently, it is critical to leave the correct amount of margin in the hole. Too much margin and the reamer may run hard and the hole may be distorted. A reamer with too little margin will rub and wear, resulting in a poor quality hole.
The reamer's edge needs to be hard for long life; it also needs to be tough so that the tool will not fail during normal use. Proper use of a controlled small amount of material allowance ensures a long reamer life and a high hole surface finish.
In addition, if the workpiece is not held firmly in place during reaming, which can lead to chattering, the finish of the part deteriorates and the cutting edge becomes dull. Friction and extremely high heat can also cause problems during reaming, which means that effective lubrication is essential not only for cooling the tool, but also for extending the life of the reamer. Lubrication also increases cutting speed and shortens production cycle times, and also removes chips and helps improve the finish of the workpiece.