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How to Make Internal Cutouts and Plunge Cuts with a Jigsaw

Master clean interior cutouts in countertops, cabinet backs, and subflooring without breaking blades.

Published by: Sierras de CalarLast reviewed on 2 min estimated read
Jigsaw performing a plunge cut into the center of a wood panel

Cutting interior openings—such as sink cutouts, electrical outlet boxes, and floor HVAC registers—requires starting your cut inside the workpiece rather than from an outer edge.

Table of Contents View sections
  1. Method 1: The Starter Hole Technique (Recommended for Accuracy)
  2. Method 2: Freehand Plunge Cutting (For Rough Framing & Subflooring)
  3. Frequently Asked Questions

For kitchen countertops, fine cabinetry, and precise electrical junction boxes, drilling starter pilot holes is the gold standard:

  1. Mark Your Opening: Accurately trace the cutout perimeter with a fine pencil.
  2. Drill Corner Relief Holes: Chuck a 3/8 in. or 1/2 in. spade or brad-point bit into your cordless drill. Drill one hole in each of the four corners, keeping the bit tangent inside your layout lines.
  3. Drop the Jigsaw In: Insert the jigsaw blade into one starter hole, line up the shoe flat on the work, and cut cleanly to the next corner.
  4. Support the Center Slug: Clamp or screw temporary wood cleats across the cutout so the heavy center piece doesn’t drop prematurely and tear out the final corner.

Method 2: Freehand Plunge Cutting (For Rough Framing & Subflooring)

In subflooring and framing lumber where corner appearance does not matter, skilled operators can plunge cut directly without pre-drilling:

  1. Select a Plunge-Tip Blade: Use an aggressive wood blade with a sharp pointed tip (e.g., Bosch T 144 D).
  2. Position the Shoe: Tilt the jigsaw forward so the front lip of the base plate rests firmly flat on the lumber, with the blade suspended a half-inch above the surface.
  3. Start the Motor: Squeeze the trigger to reach full cutting speed (3,000+ SPM) before touching wood.
  4. Slowly Pivot Downward: Use the front lip of the shoe as a hinge, slowly lowering the blade into the timber until it breaks through, then flatten the shoe and complete your pass.

Read our Countertop Sink Guide and explore our US Jigsaws.

Frequently Asked Questions

Can any jigsaw blade make a plunge cut?

No. Plunge cuts require blades with pointed plunge-tips, such as the Bosch T 144 D or T 101 B. Round-tip metal blades will skate dangerously across the wood.

Is it safer to drill starter pilot holes or plunge cut?

Drilling starter holes (at least 3/8 in. or 1/2 in. diameter) in each corner is always safer, more controlled, and guarantees perfectly square 90-degree corners.

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