Auger Bit vs Spade Bit

January 06, 2021

Auger Bit vs Spade Bit

Auger Bit vs Spade Bit

Woodworkers and artisans have tons of options when it involves drill bits. Drill bits are used for wood and metal cutting, and there are various types of drill bits available for the same. Auger bits and spade bits both belong to the same category but have different characteristics. Spade bits are less costly, auger bits leave a cleaner hole. There's a minimum of one sort of bit for creating almost any kind of hole in any type of material. But with many options comes more confusion in choosing the most straightforward bit for the work. It is undoubtedly the case with auger bits, and spade bits, each of those bits was built with specific sorts of drilling in mind.

What is an Auger Bit?

Auger Bits feature a single-spur leading edge, making it possible to drill clean holes in dense, dry lumber with ease. These bits even include a little corkscrewed tip that eliminates the necessity to use pressure while drilling.

Most auger bits include larger-than-average fluting. It enables the bit to effectively channel wood chips and debris out of the opening while the bit is in motion. Most auger bits make use of a hexagonal shank, unlike the quality round shank used on most drill bits. It provides a safer connection between the bit and, therefore, the drill, which successively improves the torque translation rate during the drilling process.

What Is a Spade Bit?

Spade Bits are sometimes referred to as "paddle bits" because they appear as a paddle. Its shape is a bit distinctive due to its squared, flat head. This head is typically sized such that any hole made thereupon will match the head's width. Making holes with these bits isn't too challenging, either, because they included a broad point on their head.

In practice, spade bits tend to make a "rougher" bore than the typical drilling bit. It is often because the flat sides on these spade bits don't always dig a wood's grain all that cleanly. It is often not usually a problem when drilling to a shallow depth. Spade bits are well-known for causing splintering if precautions are not taken when drilling through a workpiece.

Comparison Between Auger Bit & Spade Bit

  1. By Application
  • Auger bits generally drill cleaner holes with smoother sides and fewer splintering. They're commonly used for general wood drilling in construction, woodworking in gardening, and many other areas.
  • Spade bits drill holes with rougher sides and are therefore utilized in areas that will be covered. For example, when installing electrical conduits or water pipes through walls, these bits are often used because the holes will be covered by far better finishing.
  1. By Shape & Design

Design is a significant difference between these two bits. 

  • Auger bit is a spiral-shaped bit with a threaded tip at the front and two chisels at each tip's end. These chisels are liable for shaving the wood.
  • Spade drill bits are flat. They need a comfortable design shaped like a spade or paddle with two sharp lips at each end and a pointy non-threaded guidance tip.
  1. By Use
  • Auger bits require downward pressure when drilling, making it more comfortable. The threaded tip pulls the bit downwards and creates a self-driving mechanism, which will be in no time, even with just the drill's load pushing down.
  • It is not an equivalent case for spade bits. Their tips could be sharp but aren't threaded, and thus, they don't self-drive. As a result, you would like to use more downward force for quick digging. With just the load of the drill, drilling can take a short time.
  1. By Cutting Ability
  • Due to the spiral design, auger bits are suitable for precision drilling. It suggests they will dig a hole with an equivalent width because of the tool when cutting straight or at an angle. The threaded tip bites firmly into the wood to stop shifting, making the cut highly precise.
  • Spade bits are suitable for customizing the form and size of the drilled hole. The tool can be easily angled at the start or as you drill, which allows you to make a tapered hole or a smaller/larger hole than the width of the flat blade.
  1. By Drilling Depth
  • Auger bits in drill quickly and very deep. The drill's depth is due to the threaded tip, which effortlessly self-drives the tool to very deep depths. Ideally, these bits can go up to 600mm deep while creating an elegant hole. In an actual sense, the sole limiting factor is the length of the tool.

However, since the bit features a lot of area in touch with the wood (at the front and sides) when making deep holes, it's recommended to try it at slower speeds to avoid overheating.

  • As for spade bits, they're not recommended for drilling at deep depths because you'll need to apply tons of downward pressure. On the bright side, they generate less heat even at fast speeds in deep depths.
  1. By Shaving Removal
  • Apart from drilling faster and more profound, auger bits evacuate shavings very efficiently. It is often thanks to their spiral section (flight), which directs shavings to the highest, leaving the opening clear and unclogged. Single-twist auger bits provide the foremost efficient evacuation, enabling you to drill deep holes without lifting the tool.
  • However, with Spade Drill Bit, shavings usually compile above the bit within the hole, and at some point, you would possibly not be ready to see the paddle.

Therefore, this needs you to lift the bit and unclog the opening once it's filled up, which may be inconvenient if you're drilling a deep hole or drilling multiple holes.

  1. By Cost 
  • Auger bits are a bit expensive due to their design and shape.
  • Spade bits are very affordable. Their simple flat design makes them cheaper than augers, and this is often quite logical because the fabric wont to build them is a smaller amount.



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