In our complete guide to hole saws, we explain exactly what they're used for, how to use one and which one to use and when.
What is a Hole Saw?
The hole saw is a cylindrical shaped saw blade attachment designed to be used in conjunction with power drills to cut out perfectly round holes. They are extremely popular in the electrical and plumbing trade, and are much more efficient than flat and twist drill bits in applications that require drilling big, deep holes or enlarging existing ones.
In this Toolstop guide, we'll explain everything you need to know about the hole saw, how to use one and what applications they work best for.
Hole Saws Explained
A hole saw is capable of cutting holes with a much larger diameter than a standard drill bit. They create a hole in the workpiece without cutting up the core material.
The hole saw is mounted onto your power drill via an arbor which is used to grip other moving tool components. The arbor can carry a drill bit so that prior to cutting you can make a pilot hole in the material to reduce walking. Though handy, this isn't essential and not all hole saws require one.
Because the hole saw only cuts the perimeter of the material and not the core material itself, they are often a preferred choice for making larger holes. The same hole can be made much faster and using less power than with a standard or flat drill bit.
Holesaws come in many sizes and diameters and can be used to cut multiple materials. When buying a hole saw or hole saw set, it's important to think about the materials you're cutting and the finish you require. The diameter a hole saw can cut is determined by the diameter of the holesaw itself and how deeply it can cut is determined by the working length. Some may come supplied with a detachable arbor, some with a fixed arbor, and some without one at all. In this case you would need to purchase one seperately. Luckily, at Toolstop, we have a huge selection of hole saws, arbors and hole saw sets.
Parts of a Hole Saw
The hole saw is made up of cutting teeth, slots, and sometimes a pilot drill and arbor (as explained above).
The teeth will either have a variable or constant tooth pitch and are usually set at a 60° angle to cut through the material easily. Variable pitch is when the distance between the teeth varies. This provides a smoother cut with reduced wear on the blade. A constant pitch is when the distance between those two points remains constant. They cut a little slower than variable pitch but make a finer cut.
Hole saws will come with differing TPI's (teeth per inch). The higher the TPI, the slower the cut but smoother the finish. The lower the TPI, the faster the cut but it will be less smooth.
It's handy to note that the higher the TPI, the less likely the hole saw is to tear your workpiece. The lower the TPI, the more likely this is. We typically advise that 1-4 teeth per inch equals a low TPI, whilst 10+ teeth per inch equals a high TPI.
You will notice that each hole saw contains slots in its sides. Their purpose is to allow chips and dust to escape.
How to use a Hole Saw
Hole saws can be used for many applications. Typical ones include, but are not limited to, installing drainage pipes and making holes for pipework and wiring.
Once you have determined the size of hole you need to cut and have chosen a hole saw suitable for the material you're cutting, using one is actually pretty simple. Follow our steps below:
- Insert the arbor via the back of the hole saw
- Screw the hole saw onto the arbors thread until it is secure
- Insert the arbor into the drill chuck and tighten it until you get a secure hold
- If your arbor doesn't come with a pilot drill bit, you may want to drill a pilot hole yourself (although this isn't essential)
- Line your hole saw up with where you want to cut
- Start off by drilling slowly and gradually increase the speed of the drill
- Occasionally back the hole saw out of the hole to clear dust
- Once you have successfully drilled your required hole, remove the waste material from your hole saw
It really is as simple as that. Please note that it is important that you always make sure you’re using an appropriately powerful drill for hole cutting and that you equip yourself with suitable PPE.
Image: WonkeeDonkee Tools