Everything You Need to Know about Spade Bits

December 02, 2020

Everything You Need to Know about Spade Bits

Everything You Need to Know about Spade Bits

Spade Drill Bits are also referred to as paddle bits and are excellent flat blades. They're commonly employed by tradesmen like electricians and plumbers for drilling holes in studs in walls for running wiring or pipes. Still, they even have an area within the woodshop for drilling on fair woodworking projects.

What is a Spade Bit?

The spade bit is a flat, broad blade of a bit that features a pilot point attached to a 1/4-inch diameter shank, which is chucked into both regularly-chucked drills and quick-chuck impact drivers. Each fringe of the spade bit's flattened portion is sharpened, and therefore the bottom corners of the sharpened area have a pointed tip, counting on the design and brand of the bit. 

Because the drill motor turns the bit, these two sharpened bottom edges will probe the wood stock round the center pilot point, shaving wood out of the opening during a corkscrew-like manner. If the Spade Bits cutting edges are incredibly sharp, very long shavings are sometimes produced by the drilling action.

How to Use the Spade Bit?

A bit is comparatively easy to use, but unlike a twist drill, which is somewhat forgiving, the shank of a bit needs to be perpendicular to the workpiece while drilling. 

To use a spade bit:

  • Mark the middle point of the opening to be drilled on the wood, and chuck the shank of the bit into the drill.
  • Align the purpose of the pilot tip of the bit with the mark on the wood and adjust the hand-held drill's angle so that the shank of the Spade drill bit for metal is square and perpendicular to the surface of the wood.
  • While employing a drill press, the bit's angle should already be square to the wood's surface, unless the drill table isn't square to the motor.
  • Press the trigger of the drill slightly to interact with the motor and switch the bit slowly. Hold the drill as still as possible so that the pilot point stays aligned with the mark on the wood because pilot tips can often "walk away" from the opening's intended center point. Some woodworkers will drill a little pilot hole employing a small-diameter twist bit, then proceed with the Spade Drill Bit pilot tip positioned within the pilot hole.

Once the pilot tip is in situ and engaged with the wood, increase the speed to drill the opening. Continue drilling until you reach the other side of the wood, and therefore the bit pokes through to finish the opening and 1-3/8" X 6" size is the largest spade bit sizes.

When the bit's complete width emerges on the backside of the workpiece, slow the speed of the motor and punctiliously extract the bit.

Tips for Using a Spade Bit

One common issue with spade bits is that they tend to splinter and "blow out" the opening's backside. This blow out can often be quite unsightly on a fine woodworking project. 

There are various methods for drilling clean holes with a spade bit, such as: 

  • Tightly attaching a sacrificial board to the backside of the workpiece when drilling, OR
  • Drilling partway through the workpiece until the pilot point penetrates through the wood, then reversing the board and completing the opening by drilling from the backside.

It's a mistake to drill at a slow speed when employing a bit. Although a slow pace is essential as you position the brad-point and begin the opening, you should increase the speed as soon as the hole is started. It may produce a cleaner cut with smoother edges.

Conclusion

Spade bits must be extremely sharp to chop effectively. A workshop can resharpen your space bits—or you'll roll in the hay yourself with a mill file or bench grinder. The cutting edges should be honed at an angle of about 10 degrees.