The One-Two Punch

Placing drilled holes exactly where you want them.

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Having trouble placing drilled holes exactly where you want them? Give them the guidance they need with the old one-two…a prick punch followed by a center punch.

What’s the difference? The business end of a prick punch is sharpened to a fine, acute point, much like a sharpened pencil. The center punch is ground to a wide, flat angle, perhaps 140° total, a little more than the typical 135° drill point (Fig 1).

Fig. 1

The sharp prick punch sets the precise location. Place it exactly where you want the hole (using a magnifier if necessary), then lightly tap with the hammer. The resulting mark (Fig 2-a) guides the center punch, which forms a low-angle dimple (Fig 2-b), which guides the drill (Fig 2-c).

Fig. 2


Dan Horton says he is “just a homebuilder”. He has been a pilot more than 30 years and currently flies a custom RV-8.

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