A hole saw is a tool that is used to cut circular hole in various materials. A hole saw features the teeth that allow it to shear through the materials in a single pass, and produce a disk of the materials being cut. Because a hole saw features teeth that are arranged in a circle, hole saws is usualy more efficient than a twist drill or a spade bit if the required hole is larger than one-half inch in diameter.
If the correct size of the hole saw is used in the correct type of hole saw, the resulting cut will have no splinters, and the teeth of the hole saw wont dull too quick. Hole saw sizes comes in a variety of sizes. Smaller sizes, such as a 1/2-inch size, are typically used to cut holes in electrical box.
Hole Saws: Types, Sizes and How to Use Them
Larger sizes, such as a 3-inch size, are used in cutting hole in materials like HVAC duct. The size of the arbor and mandrel of the tool must increase with the size of the hole saw. Small sizes of hole saws use a 5/32-inch arbor size, but larger sizes requires a 1/4-inch arbor size to handle the additional torque that the larger size of the tool creates.
If you use an arbor that is too small for a large size of hole saw, the tool will wobble. Wobbling of the hole saw will result in the cutting of an oval shaped hole. The type of material that is to be cut will determine the type of hole saw that is used.
Bi-metal hole saws are among the most common. Bi-metal hole saws have high-speed steel cutting teeth attached to the tools flexible steel body. These types of hole saws can cut wood, aluminum, PVC (polyvinyl chloride), and even mild steel.
However, they cant be used in materials that contain masonry. For these types of materials, such as concrete and brick, a carbide grit hole saw should be used because the carbide grit will grind against the masonry material. For very hard materials, such as porcelain or glass, a diamond grit hole saw is used because these saws contain synthetic crystals that enables them to last in these types of materials.
Using the wrong type of hole saw can lead to the hole saws burn out or the breakage of the teeth of the saw. The material that is to be cut will determine the way that the hole saw is to be used. For instance, if the material being cut is wood, the user will use high speed for the saw to avoid creating splinters.
If the material contain steel, however, the RPM of the tool should be lowered, and cutting oil should be used. The cutting oil cools the teeth of the saw and also provides lubrication for the teeth. If cutting oil isnt used on steel material, the steel will overheat and the teeth of the saw will become ruined.
For PVC materials, the saw should be backed out of the hole that is being cut in the material to remove the plastic debris. For masonry materials, a hammer drill should be used with the saw, as well as a constant spray of water to cool the saw. The drill and the mandrel are two components of the tool.
A corded heavy-duty drill is generally better for cutting with a hole saw than a battery powered drill. This is because the corded drill can provide more torque, which is required for the use of a large size of hole saw. The mandrel is the component of the tool that attaches the hole saw to the drill.
If the wrong type of mandrel is used for the saw, the saw will spin loose from the mandrel while in operation, creating irregular shaped holes. To properly use a hole saw, certain procedure should be followed. First, a starter divot should be punched into the area where the hole is to be cut.
This will prevent the saw from slipping on the material. Second, a scrap board should be used underneath the material that is being cut. This will prevent burrs from forming along the edge of the cut out of the material.
Third, the RPM at which the tool is used should be decrease for larger sized saws. The cutting of larger sized holes creates more heat in the material. Thus, decreasing the RPM of the drill reduces the amount of heat created.
Lastly, hand pressure should be applied to the saw, but not too much. Applying too much pressure to a hole saw will dull its teeth. Using a dull saw will create more heat in the material, as well as cut larger than the intended size of the saw.
