Understanding Reamers and Their Functions
A reamer is a type of rotary cutting tool used in creating a straight and accurate hole in a workpiece. It is commonly used in metalworking and woodworking to enlarge or finish a hole that has already been drilled, bored, or punched. This tool is designed with multiple cutting edges arranged along its length, with a slight taper from the shank to the tip. While reamers come in different shapes and sizes, they are generally selected based on the size of the hole that needs to be produced, the type of material being cut, and the desired finish of the hole.
Measuring Holes Accurately
Prior to selecting the appropriate reamer size, it is essential to measure the hole accurately. Various measuring tools, such as a dial caliper, micrometer, or vernier caliper, can be used to determine the diameter of the hole. To obtain the most accurate measurements, ensure the measuring tool is clean, and the hole has been cleared of any burrs or debris that can impact the precision of the reading. Take multiple readings at different points across the diameter to ensure any irregularities are identified.
Selecting the Right Reamer Size for the Job
Once you have accurately measured the size of the hole, the next step is to select the appropriate reamer size. The size of the reamer should be slightly smaller than the desired finished hole size. Generally, reamer sizes are standardized and readily available. For instance, a 3/16-inch hole will require a 5/32-inch or a 1/8-inch reamer. When working with metric units, a hole that measures 10mm will require a 9mm or 8.5mm reamer.
Choosing the Correct Reamer Type
There are several types of reamers, including machine reamers, hand reamers, and adjustable reamers. The type of reamer selected depends on the hole’s size, the material being cut, and the required precision. Machine reamers, for instance, are designed for use with a machine such as a drill press or lathe and are commonly used for high volume production work. On the other hand, hand reamers are used for smaller holes, and the user holds them in the hand and twists them to produce the hole. Adjustable reamers are versatile and can be expanded or contracted to produce different-sized holes.
Factors to Consider When Using Reamers
When using a reamer, it is imperative to ensure that the workpiece is securely clamped, and the reamer is inserted vertically into the hole to avoid any damage or breakage. Additionally, avoid applying too much pressure on the reamer and use cutting oil to protect the reamer and workpiece from heat and wear. Frequent stopping and inspection of the hole will prevent the reamer from overcutting the hole and damaging the workpiece.
