Regular drill bits are thinner in diameter and longer. Those are used to drill deep and thinner holes. But wider and shorter holes are not able to drill using such drill bits. So hole saws are really important to drill shorter and wider hole drilling tasks. A hole saw is not a kind of regular drill bit. It has been specially designed as a curved saw. So let’s see, in-depth detail about hole saws.
01. What Is a Hole Saw Used For?
Hole saws are designed with a cylindrical shape saw blade attachment to use with power drills to make perfectly round holes. Hole saws are mainly two types. Wood hole saw and metal hole saw are the.
The efficiency of hole saws compared to flat and twist drill bits in drilling large intense holes or widening predrilled holes make them an essential tool in the electrical and plumbing industry.
Here we consider hole saw as a wood drill bit.
02. Hole Saw Sizes
Hole saws are available in many sizes. Those are 14mm – 210mm (9/16 in – 8 9/32 in) in size. Below are all the available hole saw sizes in millimeters and inches.
| Hole saw sizes in mm | Hole saw sizes in inches |
| 14 | 9/16 |
| 19 | 3/4 |
| 22 | 7/8 |
| 27 | 1. 1/16 |
| 32 | 1. 1/4 |
| 38 | 1. 1/2 |
| 41 | 1. 5/8 |
| 46 | 1. 13/16 |
| 51 | 2 |
| 57 | 2. 1/4 |
| 59 | 2. 5/16 |
| 60 | 2. 3/8 |
| 65 | 2. 9/16 |
| 68 | 2. 11/16 |
| 79 | 3. 1/8 |
| 83 | 3. 1/4 |
| 92 | 3. 5/8 |
| 98 | 3. 7/8 |
| 105 | 4. 1/8 |
| 114 | 4. 1/2 |
| 121 | 4. 3/4 |
| 133 | 5. 1/4 |
| 168 | 6. 5/8 |
| 210 | 8. 9/32 |
03. How To Use a Hole Saw?
Usually, hole saws are inserted on arbors or mandrels attached to a drill driver to create neat holes. If you are trying to mount a hole saw to a mandrel, follow the following steps.
- Set the bit through the center hole, and keep screwing through the mounting plate tightly.
- Till the nubs of the plate get aligned with the holes, decompress the mounting plate.
- Push the mounting plate to the holes.
- Until the mandrel is secured to the hole saw, keep fastening the nut at the back of the mounting plate.
There are hole saws available in a range of diameters and tooth sizes. Make sure to get the appropriate size for the work.
Do not forget to pull the saw out and clean it out between the teeth to prevent saws from getting jammed up with the materials. Be careful in this process as the hole saws are more likely to be hot.
Drill at a slower speed assuring that the hole saw cuts in the right place without wandering. If the hole saw has not cut through, when the drill bit enters through the other side of the material, turn the material to the other side, aligning the drill bit with the hole. Complete the cut from the other side to prevent the material from blowing out.
04. How to Use a Hole Saw Using a Drill?
Cutting neat holes with hole saws using a drill demands talent and experience. Observe the following ways when using a hole saw with a drill.
These are the steps for using a Hole saw by attaching a drill
- Always mount the exact size hole saw on the arbor. For hole saws with a modifiable center bit, ensure it comes through past the toothed edge of the saw around 3/8 inch. Orient this with the setscrew, for a center bit flat spot on the shank.
- Fasten the set screw securing the bit. Eventually, tighten the hole saw to the chuck of a 3/8-inches corded variable speed drill. Use 18V or higher voltage drill as a lower voltage is insufficient.
- To get a flawlessly neat hole keep an even contact from the beginning. This will help to keep your drill at a proper angle.
- Bending the drill or slamming a nail with the hole saw when drilling can make the saw bind and the drill motor swivel vigorously in the user’s hands. As the strong torque hit the drill into the user’s face or sprains the wrist, hold up the drill handle against your hip or leg to avoid these situations.
- Make sure that the drill goes vertical to resist binding the hole saw.
- Do not wear loose clothing or jewelry while working to prevent them from getting tangled up in the hole saw.
- Some drills have a trigger speed lock-on button. Avoid pressing it when you drill.
05. Differences Between Hole Saw And Spade Bit
When you need to drill wider holes, you can use both hole saw and a spade drill bit. But among them, which is the best tool you should use. Below is the comparison guide; you can clearly understand these bits in detail.
| Hole Saw | Spade Bit |
| Pilot twist bit in the center | Sharp point in the center |
| Poor chip clearance | Average chip removal |
| Great for large-diameter holes with a clean finish. Cannot drill blind holes. | Ideal for drilling large-diameter holes quickly and for blind holes. |
| Provide smooth and perfect holes. | Provide rough holes. |
| Suitable for metal, masonry, and woodworking. | Suitable only for woodworking. |
| Available from 7/8 inches – to 14 inches. | Available from 1/4 inch to 1-1/2 inches. |
| Moderate speed cutting | Fast speed cutting |
| Make neat and clean holes. | With splinters, make irregular holes. |
| Slower than spade bits | Drill many holes in a shorter period. |
| More costly than spade bits. | Less expensive than hole saws. |
06. Difference Between Hole Saw And Forstner Bit
Wood hole saw and Forstner drill bits are a little bit the same due to its saw tooth. But these are completely different in its cutting method. Wood hole saw has faster-cutting speed, but the hole is not clean much. But Forstner drill bits have a slower cutting speed, and it provides a neat flat bottom cutting hole every time. For more details, you can check the below table.
| Hole Saw | Forstner Bit | |
| Usability | Used to cut through holes in thin material | Appropriate for drilling neat holes which could be blind, flat bottomed, and go completely through the material. |
| Cost | Hole saws are quite a bit cheaper than Forstner bits | |
| Hole Depth | The length of the bit or saw affects the depth of the hole. | According to the depth of the material, the hole can be flat-bottomed, yet it will punch through. |
| Quality of Cut | Gives a nice finish. Still, it will not be clean like Forstner bits. | Cut the neatest hole due to its design. |
| Speed of Cutting | Cut faster than the Forstner bit | Demands a lot of time to get a sharp, neat hole. |
07. Types Of Hole Saws
| Carbon Steel | Do not use on denser materials. Use only on thin materials such as wood, non-laminated plastic, and plasterboard. |
| Variable Pitch Bi-Metallic | Bi-metal hole saws provide high security for the user as they will not break down when used continuously. Perfect for cutting materials such as plywood, hardwood, plasterboard, non-laminated plastics, and no ferrous materials. |
| Deep Cut Variable Pitch Bi-Metallic | A forceful cutting strategy due to its updated NVP variable pitch layout and advanced tooth geometry. |
| Constant Pitch Smooth Cut | Have a continual tooth pitch constructed of hardened, heat, and friction-withstanding high-speed steel with a hard alloy structure. Perfect to use with cordless power drills (18 Volts). |
| Tungsten Carbide Tipped Hole Cutter | A heavy-task general-purpose cutter and perfect to work on plastics, wood, MDF, and ceramic tiles. |
| Welded Shank Soffit Cutter | Includes a non-detachable arbor fastened onto the base plate. Useful to cut holes in PVC, plywood, and metal. The cut depth is around 47mm. |
| Diamond-Edged Hole Saw | Have an increased heat and wear obstruction that makes them extremely durable. Although these saws have high heat resistance, it is recommended to moisten them in water to cool off the blade. Mainly used for drilling through ceramic tiles. |
| Multi-Hole Saw | Mainly for cutting various diameter holes in sizes (26, 32, 38, 45, 50, 56_ 63mm) and cutting holes till 42mm. Can be used on plywood, wood, chipboard,non-laminated plastics, non-ferrous metals, and plasterboard. Do not use stainless steel. |
08. Hole Saw Resharpening And Maintenance
- Regular cleaning expands the lifespan of the saw. Clean the saws after using them to protect them from dirt, wood fragments, and filings, which make hole saws get stuck in the material or strip and harm the saw teeth.
- When using your hole saw, do not forget to back the saw out of the hole frequently, which assists in cleaning the teeth from wood particles and dust, restraining the blade from getting hot, and preventing tooth damage.
- Use balanced pressure and ensure the hole saw teeth interact with the material in an equal manner. This will help to reduce unequal sawing and avoid tooth stripping.
- When using metals, use good cutting oil to clear chips. Lubrication assures a smoother cutting action with minimum friction, expanding the lifespan of the hole saw.
- Due to the amount of damage and friction a hole saw undergoes while using it, it is wise to replace it before the arbor.
- Always store hole saws in a secure, dry place.
09. Can I Use a Wood Hole Saw In Metal?
Normally, wood hole saws are not able to use on metals because wood hole saws are made with weak materials, and the structure is not strong to use in metals. Hence you should use a metal hole saw for the metals.
However when cutting holes in steel doors for deadbolts, cut many holes, and for metal, step up to a bimetal hole saw.
The teeth are strong as they are designed with tougher steel. Yet that does not imply they are unbreakable. Lubricate well when drilling into metal. If you can not find cutting oil, use regular motor oil.
