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Difficulty: Very hardPower Drills and Drivers

A carpenter is installing a deadbolt lock and must bore a clean, 2-inch diameter hole through a finished solid-wood door using a portable variable-speed drill and a hole saw accessory. To prevent destructive splintering (blowout) on the door's exit face, arrange the following procedural steps in the correct chronological order.

  1. 1Clamp the door securely to sawhorses and mark the precise center point for the bore.
  2. 2Chuck the hole saw arbor into the drill, ensure the drive pins engage the cup, and select the drill's low-speed, high-torque gear setting.
  3. 3Align the pilot bit with the center mark and begin boring into the first face of the door, maintaining a strictly perpendicular angle.
  4. 4Stop the drill the exact moment the tip of the center pilot bit breaches the opposite side of the door, and withdraw the tool.
  5. 5Relocate to the opposite face of the door and insert the hole saw's pilot bit into the newly created small exit hole.
  6. 6Bore inward from the second side until the central wood core plug falls out, leaving a clean edge on both finished surfaces.

Answer

The correct sequence requires clamping the door, configuring the drill for low-speed/high-torque, drilling from the first side until the pilot bit barely breaches the opposite face, and then finishing the cut inward from the reverse side.
Boring a large hole through finished wood requires preventing 'blowout'—the violent tearing of wood grain as the saw blade exits. By drilling from the first side only until the pilot bit breaks through, the carpenter establishes a perfectly aligned center point on the reverse side. Moving to the reverse side and cutting inward ensures that the saw teeth are always entering a finished surface and exiting into the scrap plug in the middle, leaving both exterior faces perfectly clean. Additionally, a 2-inch hole saw requires the drill's low-speed, high-torque mechanical gear to prevent the tool from bogging down.

Step-by-Step Solution

1
Clamp and mark the workpiece.
The door is immobilized with a clear target.
Prevents movement that could ruin the precise alignment required for a lockset hole.
2
Chuck the hole saw and select the low-speed gear on the drill.
The tool is mechanically configured for high torque.
A 2-inch diameter cut creates massive surface friction; low speed prevents the drill from binding and the wood from scorching.
3
Drill into the first face.
The saw cup cuts approximately halfway through the door's thickness.
Begins the bore cleanly on the primary finished face.
4
Stop when the pilot bit penetrates the far side.
A small 1/4-inch hole appears on the back face, but the large saw cup has not exited.
Pushing the large teeth completely through would violently tear the unsupported wood fibers on the exit side.
5
Move to the opposite side and align the pilot bit.
The saw is perfectly aligned to cut back toward the original channel.
Uses the common center axis to ensure both cuts will meet seamlessly.
6
Complete the cut from the second side.
The wooden plug is released, leaving pristine circular edges on both sides.
Because all cutting forces push inward toward the solid center of the door, exterior blowout is completely eliminated.

Key Concept

When using large diameter hole saws on finished materials, cutting must be performed from both sides to prevent exit blowout, and the power drill must be set to a low-speed, high-torque gear setting.
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Power Drills and Drivers

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