Drill and Auger

Part of Woodworking

Drilling clean holes is essential for pegged joints, dowel construction, pipe-making, and countless other tasks. Before electric drills existed, woodworkers bored holes with muscle-powered tools that are entirely buildable from scratch. Master these and you unlock the full range of joinery.

Why Drilling Matters

A round hole through wood seems simple, but it enables:

• Pegged joints — mortise-and-tenon locked with wooden dowels
• Bolt holes — for metal fasteners when available
• Pipe and conduit — hollowed logs for water transport
• Axle holes — for wheels, pulleys, cranks
• Ventilation — controlled airflow in structures
• Starting points — for cutting interior openings with a saw

Without drilling capability, you are limited to surface joinery and split-wood construction. With it, you can build furniture, machinery, and infrastructure.

The Bow Drill for Woodworking

You may know the bow drill for fire-starting, but the woodworking version differs in important ways.

Key Differences from Fire Drill

Feature	Fire Drill	Woodworking Drill
Speed	Moderate	Fast (tighter string wrap)
Pressure	Light (heat, not cutting)	Heavy (downward force)
Bit	Blunt spindle	Sharpened metal or hardwood point
Bearing block	Hand-held	Chest plate or cap with socket
Goal	Friction heat	Material removal

Building a Woodworking Bow Drill

1. Bow: Slightly curved branch, 60-80 cm long, with cord tied at both ends. Use leather thong or twisted cordage — it must handle tension without stretching.
2. Spindle: Straight hardwood dowel, 20-30 cm long, 1-2 cm diameter. The bottom end holds your cutting bit.
3. Bit: A sharpened nail, flint flake bound to the spindle, or a forged metal point. The cutting edge must be wider than the spindle to prevent the shaft from binding.
4. Bearing cap: A block of hardwood or stone with a shallow socket. Hold this against your chest or press down with your palm. Grease the socket to reduce friction at the top while maximizing cutting at the bottom.

Using the Bow Drill

1. Wrap the cord once around the spindle
2. Place the bit on your mark
3. Press the bearing cap down firmly onto the spindle top
4. Saw the bow back and forth — full strokes, steady rhythm
5. Apply consistent downward pressure
6. Clear chips periodically by lifting the bit

Tip

Lean your body weight over the drill. Your arms move the bow; your chest and shoulder press down. This frees you from arm fatigue on the pressure side.

The Pump Drill

A pump drill converts up-and-down motion into rotation using a flywheel. It is faster than a bow drill and leaves both hands free for positioning.

Construction

1. Shaft: Straight hardwood, 40-60 cm long, 2 cm diameter
2. Flywheel: A heavy disc (stone with center hole, or thick hardwood round), mounted near the bottom of the shaft. Weight provides momentum.
3. Crossbar: A flat piece of wood, 30-40 cm long, with a center hole that slides freely up and down the shaft
4. Cord: Two lengths of strong cord, tied from each end of the crossbar up to the top of the shaft

Operation

1. Wind the cord by spinning the shaft manually — this raises the crossbar
2. Push the crossbar down — the unwinding cord spins the shaft
3. Momentum from the flywheel re-winds the cord in the opposite direction
4. Push down again — continuous rotation alternating direction

Warning

The pump drill alternates rotation direction each stroke. Your bit must cut in both directions or you will just polish the wood. Use a spear-point bit ground symmetrically, not a twist bit.

Brace and Bit

The brace is the most powerful hand-drilling tool ever devised. A U-shaped crank provides enormous torque for boring large holes.

Building a Brace

1. Crank body: Bend a green hardwood branch into a U-shape, or laminate two pieces with a connecting handle. Total length about 30 cm from center of rotation to handle.
2. Top pad: A free-spinning knob at the top. Drill a hole in a round hardwood block, insert the shaft so it can rotate while you press down. Grease the bearing surface.
3. Chuck end: The bottom of the crank must hold bits firmly. Options:
   • Split socket: Saw a slot in the end, insert the bit tang, and bind tightly with cord or a metal ferrule
   • Tapered socket: Bore a tapered square hole that grips a tapered bit tang (traditional method)
4. Handle: A free-spinning grip on the crank sweep. Drill through a short cylinder and mount it so it rotates on the crank arm.

Using the Brace

Hold the top pad with one hand (or press with your chest), grip the handle with the other, and crank. The circular motion provides continuous rotation with mechanical advantage proportional to the crank radius.

Crank Radius	Torque	Speed	Best For
10 cm	Moderate	Fast	Small holes, softwood
15 cm	High	Medium	General work
20 cm+	Very high	Slow	Large holes, hardwood

Auger Types

An auger is a large-diameter boring tool designed for deep holes. Several designs exist, each with strengths.

Spoon Bit

The simplest auger. A flat or slightly curved blade with a sharpened edge, shaped like a shallow spoon.

• Pros: Easy to forge, sharpens simply, works in any wood
• Cons: Slow, produces rough holes, hard to keep straight
• Best for: Rough work, green wood, large shallow holes

Spiral (Jennings) Auger

A helical flute wraps around the shaft, pulling chips up and out of the hole automatically.

• Pros: Self-feeding, clean holes, stays straight, clears chips
• Cons: Difficult to forge, requires precise geometry
• Best for: Deep holes, finished joinery, dry hardwood

Shell Auger

A half-cylinder with a cutting edge at the tip. Used for very deep boring — historically for wooden water pipes.

• Pros: Bores extremely deep, follows grain well
• Cons: Must be withdrawn frequently to clear chips
• Best for: Pipe boring, deep mortises, log hollowing

Sharpening Drill Bits

A dull bit burns wood, wanders off course, and exhausts you.

Sharpening Procedure

1. Examine the cutting edge — identify the bevel angle (usually 25-30 degrees)
2. Use a small flat file or fine stone — work only on the bevel side, never the flat back
3. Maintain the original angle — hold the bit at a consistent angle against the stone
4. For spoon bits: Sharpen the inside curve, then lightly hone the outside
5. For spiral bits: Sharpen the cutting lip and the scoring spur separately. The spur must project slightly beyond the lip to score the circumference before the lip lifts the chip.

Warning

Never grind the outside diameter of an auger bit. This makes the hole smaller and causes the bit to bind. Only sharpen the cutting edges from the inside.

Drilling Straight

A wandering hole ruins joinery. Use these techniques to stay true.

Guide Block

1. Drill a hole through a scrap block of hardwood at exactly 90 degrees (verify with a square)
2. Clamp this block over your workpiece at the drill location
3. Insert your bit through the guide hole — it physically cannot wander

V-Block for Round Stock

To drill into a dowel or round piece, rest it in a V-shaped cradle cut from a scrap block. This centers the work and prevents rolling.

Depth Stops

Wrap a piece of leather or cord around the bit at your desired depth. When the flag reaches the surface, stop drilling. For more precision, drill a hole through a wooden block and slide it onto the bit as a physical collar.

Visual Alignment

Place a try square next to the bit and sight from two perpendicular directions. Have a helper check the second angle while you watch the first.

Boring Large Holes

Holes larger than 25 mm require special approaches.

1. Start small: Drill a pilot hole with a small bit, then enlarge with progressively larger bits
2. Use an expansive bit: A bit with an adjustable cutter that swings out to the desired radius (requires metalworking capability)
3. Drill a ring of small holes: Mark a circle, drill overlapping holes around the perimeter, then chisel out the center waste
4. Hot iron method: For rough holes in green wood, heat an iron rod and burn through. Crude but effective for non-structural work.

Tip

When boring through a workpiece, drill from both sides. Drill halfway from one face, flip the piece, and complete from the other face using the pilot hole to align. This prevents blowout on the exit side.

Making Wooden Dowels

Dowels are the universal fastener of woodworking. A dowel plate makes them quickly and consistently.

Building a Dowel Plate

1. Find or forge a flat piece of steel, at least 5 mm thick
2. Drill a series of holes in decreasing sizes — 20 mm, 16 mm, 12 mm, 10 mm, 8 mm, 6 mm
3. Chamfer the top edge of each hole slightly to guide the blank in
4. Mount the plate over a hole in your workbench (so the dowel can pass through below)

Making Dowels

1. Rive blanks: Split straight-grained wood into rough squares, slightly larger than your desired dowel diameter
2. Rough round: Whittle or plane the blank to a rough octagon, then round
3. Drive through the plate: Start with the largest hole that the blank fits through. Place the blank in the hole, drive it through with a mallet. The steel edges shave the blank to a perfect cylinder.
4. Step down: Move to the next smaller hole if you need a thinner dowel
5. Dry: Air-dry the dowels before use if made from green wood

Dowel Diameter	Typical Use
6-8 mm	Furniture pegs, small joints
10-12 mm	General joinery, drawer pins
16-20 mm	Timber frame pegs (treenails)
25 mm+	Structural pins, axle bearings

Tip

For the strongest joints, make dowels from wood that is drier than the surrounding timber. As the joint absorbs moisture, the dowel swells and locks tighter. Oak, ash, and hickory make the best dowels.

Drill and Auger — At a Glance

Boring holes unlocks pegged joinery, dowel construction, and structural work. The bow drill gives you basic capability, the pump drill adds speed, and the brace-and-bit provides the torque for serious work. Choose your auger type based on hole size and depth — spoon for rough work, spiral for precision, shell for deep boring. Always use guide blocks for accuracy, sharpen bits from the inside only, and make your own dowels with a simple steel dowel plate. These tools require no electricity, no factory parts, and will serve you for a lifetime.