Hole saws are commonly used to cut large holes in materials such as wood or metal to create a smooth, round hole. The most common type is the arbored hole saw with a pilot bit in the center. But what if you do not want to punch a smaller center hole in the material that you are cutting out?
Can You Use a Hole Saw without a Pilot Bit?
The answer is yes, you can use a hole saw without a pilot drill to create a hole in wood, metal, or other material without creating a pilot hole. This is quite useful for two purposes.
- When the main purpose is to enlarge an existing hole.
- To create a circular piece from the material that you are cutting into. For those who use such shapes in the creation of other projects, the absence of the drill bit is quite desirable.
However, hole saws that do not have a pilot bit will require the use of a drill press or guiding plate in order to work properly.
1. Using Hole Saw on Drill Press
Without the pilot bit drilling into the center of the workpiece, the hole-saws tend to wander around especially at the beginning of the cut. The drill press or a milling machine solves this problem.
Hold the hole saw in the drill chuck. Place the workpiece on the drill press table and bring the tool close to the work to position the workpiece. Secure the workpiece with clamps to ensure that it won’t move during cutting. Switch on the machine and bring the tool to the work to start cutting.
It is important to ensure that you have sufficient clearance below the workpiece for the hole cutter to come out at the bottom end. You don’t want to spoil the table of your drill press. One way to do this is to use spacers or parallel blocks to raise the workpiece or place a scrap piece of wood below.
2. Hole Saw Guide Plates
The next method is to use a guide jig. If you are using a hole saw on a handheld drilling machine such as a cordless drill, you need a guide plate.
A guiding plate sits on top of the material and is firmly in place. The plate keeps the hole saw without a pilot bit from drifting or walking across the material. Without a guiding plate, it is difficult to near impossible to create a perfect circle.
How to Use a Hole Saw Guide?
The guide itself can be a DIY jig or a professional guide that you purchase in a store.
Commercial Guides
This is normally a piece of hard material such as steel with different size holes that will fit on top of the material. Secure the guide and place the hole saw inside and press the trigger to start sawing.
Adjustable Guide Jigs
You can also get adjustable guides. These are mainly used with diamond hole saws for cutting holes in tiles, granites, masonry, and stones.
The adjustable hole saw guide jig comes with a rubber base and plastic or aluminum housing. It has four hardened ball bearings that will open uniformly to adjust to the required hole size.
- Place the hole saw inside the guide jig between the rollers and adjust it according to the diameter of the saw.
- Remove the hole cutter and place the jig exactly where you want to drill.
- Press the suction-cup and lock the jig in place.
- Now you are ready for cutting the hole accurately.
How to Make a DIY Hole Saw Guide?
You do not need to purchase a separate guide if you already have material with the hole cut into the center. You can make one on your own by using a scrap piece of wood.
- Use the hole saw with a pilot bit to cut the right size hole into the scrap wood.
- Unlock the set screw and remove the pilot drill
- Secure the scrap wood on top of the material you wish to create the hole
- Set the hole saw inside the guide and press the trigger to begin
Be sure to use scrap wood that is thick and strong enough to act as a proper guide. Plus, set your hole saw firmly inside before you press the trigger.
Using a Hole Saw to Enlarge an Existing Hole
With the DIY guide that you have made, you can create several holes before it gets worn out. Since the hole saw has cutting teeth only on the periphery, it will not enlarge the hole in the guide jig. However, keep in mind that you have to align your power drill axis to the guide hole axis. If you tilt the drill too much, the jig will get damaged.
For maximum efficiency, use quick-release clamps to hold the guide in place and then move them to the next location.
If you plan on creating circular material for the long term, consider using a strong piece of scrap metal for your guide. It will last far longer than wood with the proper care. Plus, the metal will not have to be as thick as the wood which may make it easier to clamp into place.
Summary:
So yes, you can use a hole saw without the pilot bit. You will need a bit of preparation, but with the proper guide, you can create hole after hole with relative ease.
Dan Miller is a professional toolmaker with extensive experience in the metalworking and tooling industry.
An avid DIY enthusiast and passionate hobbyist woodworker, Dan shares his expert knowledge here.