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Which tool could be used at home to produce a similar result?

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    Note that a recess to cradle shelf pins is usually considered optional, unless you expect to put pulling force on the shelves
    – keshlam
    Feb 24 at 18:11

1 Answer 1

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The normal approach for drilling half-round holes would be to clamp a scrap piece of material tightly to the work piece, and then drill normally on the join. When the two pieces of wood are separated, you're left with a half-hole in the work piece.

As long as the scrap is clamped tightly and is of similar strength material (e.g. another piece of melamine) this should produce a very clean edge as there is nowhere for the material to tear out to as the drill cuts through it. Of course practice first on some scrap.

To get the flat bottom, you'd need to flat bottomed drill bit, though I'd probably start with centre-drill or regular drill bit to help guide the flat bottom bit into position.

You could alternatively use the same technique, but using a router. With a straight plunge bit or other flat bottom router bit, use that to drill out the hole which may produce a cleaner result and give you better control in positioning the hole.

The chamfered edge can be done with a countersink before separating the two bits of wood.

Diagram of making half-hole by clamping on scrap piece


Fun fact: when IKEA make these in the factory, because the shelves are symmetrical, the "scrap piece" will actually likely be another work piece. That way they can drill out two shelves simultaneously without waste, probably using some giant industrial CNC or manually with a jig.

You can use the same technique if you need to drill out recesses into multiple shelves. Clamp the two shelves back to back (instead of using a scrap piece), and drill as proposed above. This will produce half-round holes in both shelves with half the effort.

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  • FWIW Roman's pictured cut would have been done on end, two pieces at a time, perhaps using a specially-shaped flat drill with no brad point guide and the round-over edge included in the drill profile. A dowel-drilling machine with appropriate fencing could do it. A router bit that can produce a half-round bottom would also produce a half-round end shape instead of the square end shape. Feb 24 at 14:10
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    If you are doing more than one shelf, clamp two shelves together bottom-to-bottom, and no scrap required.
    – Ecnerwal
    Feb 24 at 15:09
  • @Triplefault This was probably done using a router with the spindle axis parallel to the surface, the same way people are proposing to drill it.
    – Jasen
    Feb 25 at 7:00
  • If it's particle board, a simple chisel could do the job.
    – Huesmann
    Feb 25 at 17:25
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    A router is great for doing this BUT if you are not careful it can give you massive chip out at the surface. This is avoidable if you use tape over the top or if you pre score the surface
    – Dizzy
    Feb 26 at 12:52

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