When it comes to construction, the use of drills for making holes cannot be overemphasized. For those who may not know, a drill is a machine with a fast-rotating tip used to make surface holes.
To use a drill to make holes, you will need certain attachments. The two most common attachments used in drills are twist and spade bits.
Spade bits can make holes in various surfaces such as wood, plastic, studs in walls, and plywood. However, unlike twist bits, they are unsuitable for metal surfaces, as this can damage their edges, leaving you with a crappy-looking hole.
To learn more about spade bits, how to use them, and when and where you can use them, continue reading. We will cover everything you need to know about space bits below.
What are spade bits?
A spade bit is a flat-shaped drilling bit attached to a drilling machine to bore holes in wooden or plastic surfaces.
Spade bits come in different sizes, ranging from a quarter inch to an inch and a half (¼” to 1½”). Each spade bit has a flat top in the shape of a spade. Its edges are sharp at both ends, which aids in widening the holes and removing wood shavings and other waste materials from the bored holes.
They are used to make multiple larger holes quickly and with better precision. They are used mostly by plumbers and electricians to drill holes in plastic pipes, studs in walls, and other wooden structures.
How do Spade Bits work?
A spade bit is a rod with a flat surface on one end and a shank about a quarter-inch long.
The spade bit’s shank is the part connected to the drilling machine. It is hexagonal with flat surfaces, which allows it to stay in place when attached to the drilling machine.
The flat surface has a sharp pointed center point, a pilot for making precise holes. They guide and prevent the spade bit from derailing off course when drilling. The spade bit spurs make a pre-cut circle as the drilling machine presses down on the wood. At the same time, the spade bit lips shave off the unwanted wooden materials in the pre-cut circle.
As the spade bit rotates, the center point guides it into the wooden surface. Then the spade bit spurs make the pre-cut circle while the spade bit lips clear off all wood shavings.
When to use spade/paddle bits?
When it comes to drilling precise holes on wooden surfaces, there are several drill bits you can choose from. By the way, spade bits and paddle bits are the same things.
Spade bits are great for drilling large diameter holes that are likely to be covered up or in areas where it won’t be obvious. Drill bits capable of producing larger holes, such as twist drills, are mostly incompatible with hand-held drills. Drill presses are more suited for larger diameter twist drills.
A spade bit would be the best option when using a hand-held drill to make a large rough hole.
Another good option would have been the forstner bits. But using them would require you to keep the drilling machine at a 90-degree angle to the working surface throughout the drilling process. This can be challenging, making forstner bits best suited for drill presses.
Electricians and plumbers mostly use spade bits attached to hand-held drills to bore holes in wood and plastic to insert wires and pipes.
How to use Spade Bits?
Spade bits attached to hand-held drills are easy to use. To successfully use the spade bit, follow these simple steps:
- Fix the spade’s shank bit into the drilling machine’s throat.
- Mark the point at which you wish to drill. Position the center point of the spade bit on the marked point you made earlier. Adjust the hand-held drill until it is perpendicular to the surface of the wood. When using a drill press, the spade bit, when connected correctly, should already be perpendicular to the wood surface.
- Slightly depress the drill trigger to turn the spade a bit slowly. Continue this process until a pilot hole is created. Pilot holes are meant to guide the center point forward and keep it from derailing. Ensure you hold the drilling machine steadily and perpendicularly when creating the pilot hole.
- Increase the speed of the drilling machine when you notice the spade bit is in place. Gently press down on the drilling machine as you continue to drill.
- Once you notice the entire flat part of the spade drill emerges from the backside of the wood, slowly reduce the speed of the drill and pull out the bit.
Tips for Using a Spade Bit
- For a cleaner cut, never drill at a slow speed when using spade bits. It would be best if you only used slow speed when creating the pilot holes. After that, proceed to use full speed.
- Never use a blunt spade bit. Always sharpen your spade bits before use so as to get a smoother and faster cut.
- Most of the time, spade bits can cause the back of the wood to blister or blow out. To prevent this, add another piece of wood at the back so the spade bit can continue drilling into it instead of bursting out the other side.
How to sharpen spade bits
There are a number of methods you can use to sharpen your spade bits. They include:
- Using a bench grinder
- Using a file
- Using a drill sharpening machine.
All these methods follow similar steps when sharpening.
Start by sharpening the spade bit’s flats (also known as lips). This part of the spade bit is very important as it is responsible for removing wood shavings: the sharper the flats (lips), the faster the drilling. Blunt lips are not only slow but can heat up very easily.
Proceed by sharpening the center point. The center point is important in drilling precise and accurate holes. A spade bit with a sharp center point would easily stay put on the pilot point. Spade bits having a blunt center point will easily derail from the pilot point, causing more damage to the surface of the wood.
The third step involves sharpening the spurs of the spade bits. The spurs are responsible for making a pre-cut circle on the wood surfaces. A sharp spur will effectively make a precut, thereby making it easier for the spade bit lips or flats to remove the remaining bits of wood left.
Advantages of the spade drill bit
- Spade bits can be used over a number of other surfaces apart from wood. They can also be used on plastics, rubbers, and, in some cases, soft metals.
- Another advantage of the spade bit is that it can be used to drill multiple holes faster compared to other drilling bits.
- They are also cheaper and can make large holes.
The disadvantages of using spade bits
- One disadvantage of using a spade bit is that it causes splintering at the other end of the wood. This is more prevalent in dry woods.
- Another problem associated with the spade bit is that it needs to be spun really fast to get a clean cut. As a result, unlike the twist drill, they cannot be used in hand-powered drilling tools.
Spade bits are less expensive than other kinds of boring wood bits
Another good reason to choose spade bits over other wood boring bits is its cost benefit. Spade bits are less expensive than other bits available on the market. A 6-pics set of spade bits starts from $10, whereas auger bits for wood will cost $25. A 7-piece forstner bit set is more expensive, and you have to count more than $50 for that.
Why would you choose a spade bit over other drill bits?
One major reason most people choose a spade bit over other drilling bits is the size of the hole they intend to make. Spade bits come in a range of sizes compatible with both hand-held drills and drill presses.
For larger holes, the spade bit is the best option, especially when using a hand-held drilling machine. Twist drills with larger diameters are not compatible with most hand-held drills.
They are also cheaper and faster when compared to other drill bits.
Frequently Asked Questions About Spade Bits
What sizes do spade bits come in?
The sizes of spade bits range from 14 inches to 1 14 inches.A standard drill set always includes these common sizes (3/8″, 1/2″, 5/8″, 3/4″, 7/8″, 1″)
What size of spade bit is good for a door latch?
Use a 7/8-inch spade bit for door latches.
Spade bits are important tools needed for drilling large holes in wood. They can also be used on plastics and some soft metals.
Note that twist bits and Forstner bits can also be used to drill large holes but have their own little disadvantages. For example, twist bits capable of making large holes can only be used on drill presses. Also, Forstner bits are difficult to hold in a perpendicular position when using hand-held drills.
Also, ensure your spade bit is properly fastened into the throat of the drilling machine. A loose spade bit won’t rotate properly and can cause injuries.