What are Different Parts of a Spade Bit

April 11, 2022

What are Different Parts of a Spade Bit

A spade bit or paddle bit is a wood drill bit used to cut and drill through wood, plastics, and thin metals. A spade bit is easier to use than other drill bits due to its simple design.

The spade drill bit is flat and has a sharp-edged center point and two lips and spurs to cut and drill through all types of wood. Some versions feature a long shank for deep and more effective drilling.

Let us understand each part of spade bit in detail.

Different Parts of a Spade Bit

  • Spade Bit Center Point
  • Self-feeding Bit
  • Spade Bit Spurs
  • Spade Bit Lips
  • Spade Bit Shank
  • Spade Bit Cable Hole

Spade Bit Center Point

Spade bits have a sharp-edged center point that acts as a pilot. The center point is the first part of the spade bit that comes into contact with the workpiece. The Center point guides the drill bit to move smoothly inside the workpiece. It also prevents the drill from slipping off the workpiece.

Read More: Spade bit vs Drill bit

Self-feeding Bits

Self-feeding bits are drill bits that have a guide screw tip at the top.

Drill bits that have a guide screw tip (self-feeding tip) on the top are called self-feeding bits. Such self-feeding bits are used by the DIYer to reduce the amount of effort required while drilling.

Some specially designed spade bits have a guide screw tip instead of a center point. However, the function of both is the same which guides the drill bit to move inside the workpiece. Instead of a full guide screw, some self-feeding spade bits have a center point with threads cut along the edges. 

Spade Bit Spurs

After the center point, the spurs enter the workpiece, since the spurs have sharp edges, they cut the hole in a circular shape. The spade bit's spurs are primarily responsible for effectively cutting the workpiece from the outside.

Some spade bits do not have spurs. The lip of this type of spurless spade bit is relatively close to the workpiece at its farthest corners. And since they don't have sharp point edges (responsible for precise cutting) they produce rough holes.

Read More: Spade bit vs Auger bit

Spade Bit Lips

After the spurs, the lips enter the workpiece. The lips of the spade bit are responsible for cutting material from the bottom of the hole. They also remove waste material from the borehole while drilling. Most of the cutting work is done by spade bit lips.

Spade Bit Shank

The shank is the end part of the spade bit that connects the bit with the drill and is grasped by the chuck. Although there are different types of drill bit shanks, the hex shank is the most common among drill bits. Spade bits usually have a hexagonal shank.

This is because the long, flat cutting edges of a spade bit require a lot more force (turning force) than other drill bits. A cylindrical shank can rotate even if the driver's jaw is very tight.

Spade Bit Cable Hole

The cable hole feature is not available in all types of spade bits. The cable hole on a spade bit is used to bring the electric cables back through the boreholes. From the storage point of view, they are also used to hang the spade bit on a wall-mounted rack.

Also Read:

  • What is a spade bit
  • How to sharpen spade bits



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