Flat bottom holes with hand brace?

Well, here’s how I’ve done it in the past to get to the next step which is a bolt embedded in a wooden block that is then shaped by hand or turned in a lathe – I’ve done both.

I’ll emphasise that it needs some accurate drilling and cutting, but it is by no means a precision job. Easier to show than to write about, but here goes………

Select your bolt. Measure the outer diameter of the thread. You’ll need a drill this exact size.

Measure the distance across the flats (NOT THE POINTS) of the Hex head. You will need a drill this diameter – Ideally a Forstner type or a spur-point drill, ideally a drill without a long lead-screw. A flat bottom to the hole is nice to have but not essential in my opinion.

The blank that forms the head needs to be in two pieces: The first is the larger and forms the back part. The second is the same size, but only ¼ inch – 6 mm – thick. If you have a single piece, cut a 1/4 inch slice from it. Alternatively you can contrast two different pieces and make a feature of it.

Mark the centre of this thinner piece and drill it with the smaller drill, then smooth the sides flat and parallel.

Drill a hole with the second, larger drill vertically into the centre of the larger piece as deep as the Hex head of the bolt – no more. The drilled hole needs to be central, upright and the depth of the bolt head – no more or less – don’t worry about being bang-on precise.

Centre the bolt head as exactly as you can over the hole and mark the 6 sides equally around theedge with a knife point. With a small bevel-edge chisel, plunge each side vertically downwards to make a hexagonal hole that the bolt sits in a tightly as possible. At this point you can make the base of the hole as flat as you like, but It just needs to recess the bolt-head which will be entirely encased. Any slack bits can be filled with glue later.

Take the other piece of wood and insert the bolt. Ensure that both faces mate evenly, Run the nut down the bolt to ensure that it sits vertically against the narrow piece and will be centrally located along the axis of the blank when you glue up. You can now bed the bolt head in the hole with some glue

Align the grain with no gaps and complete the glue-up. If the faces are flat and from the same bit of wood, you should not see a glue joint and the nut will hold the bolt on its axis.

Shape the wooden head as you wish.

Good luck

P.S. – I’m assuming that the grain runs at right angles to the bolt: If the grain is aligned to run in the same direction as the bolt, then you’ll need to consider a glue that will grip end-grain. Many glues are less effective in strength on end grain in my opinion.

Jukka Huuskonen wrote:

Are links somehow disallowed here? My posts won’t get through if I have a link in them.

My experience is you get one link.

Two links and the posts don’t go through.

That tool looks like it would be very useful for trimming tenons, due to its asymmetric design. I believe you’ve used a veritas router blade? And I assume a large eye bolt runs through the centre of the tool to the tightening nut?

Nice work, thanks for sharing.