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Spy bolt

Why

Because playing with a new lathe is fun. Because Bond is a wannabe and Q is the real man. And as a homage to the spy-vs-spy games of the 1950's era.


Bolts

Hex bolt with removable head

The source material was an M8 bolt with a hex head.

Part of the bolt, adjanced to the head, was cut down to 5mm diameter, then cut off the remaining stem. A longitudal hole, 4.5mm diameter, was drilled along the axis of the stem. A male M5 thread was cut on the head-stub, and a matching thread was cut in the hole. Few millimeters of the entrance of the hole were widened to 6mm diameter, to facilitate the ingress of the part of the stub where the thread was not cut completely.

The axial alignment of the thread and the hole was not entirely optimal (let's blame it on the lathe operator's inexperience). The head is not perfectly centered on the stem, nor is it perfectly perpendicular to the stem's axis. The difference is however small enough to pass a casual check. There is an indentation visible on the end of the bolt; this one was used for the lathe center cone. A slightly different way of machining, or using another bolt as a donor of the threaded stem, can alleviate this.


Hex bolt

Hex bolt

Hex bolt, disassembled

Hex bolt, disassembled

Hex bolt, message inside

Hex bolt, message partially removed

Hex bolt, message removed

Hex bolt, message unrolled

Philips bolt with plugged end

The source material was a M8 bolt with a cylindrical Philips head, and a M5 bolt with a hex head.

The M5 bolt was cut off on a lathe, yielding a small piece of a threaded rod. A slit was cut into its end, for a screwdriver blade.

A 4.5mm diameter hole was drilled along the axis of the M8 bolt, along almost its entire length. An M5 thread was cut into its entrance.

The modification is fairly obvious on the end of the bolt, but the obviousness vanishes when the bolt is screwed into a blind hole in some other object.


Philips bolt

Philips bolt, assembled

Philips bolt, assembled

Philips bolt, assembled

Philips bolt, assembled

Philips bolt, disassembled

Philips bolt, disassembled

Philips bolt, message inside

Philips bolt, message removed

Philips bolt, message partially removed

Philips bolt, message unrolled

M12 hex bolt with plugged end

The source material was a M12x35 bolt with a hex head, and a M8 bolt with a hex head.

The M12 bolt was chucked into the lathe, centered, and a shallow hole was drilled into the center of its end. The bolt was then moved to the prismatic vise on the drill press, and a 30 mm deep 7mm diameter hole was drilled through its center. A M8 thread was then cut through the entry part of the hole.

The M8 bolt was clamped in the vise, then a 4mm deep 5mm diameter hole was drilled through its center. The stub with the drilled hole was then cut off with a hacksaw and made even with a file. Two holes of about 1.5mm diameter were drilled into its face to facilitate removal/tightening of the cap with a spanner-type screwdriver bit.


Lathe

Lathe

Lathe, ready for another bolt

Drill press with xy table and machine vise

Original bolt

Drilling on a lathe

Drilling on a lathe

Drilling the main hole

Drilling the main hole

Drilling the main hole

Cutting the thread

Drilling the hole in the lid, failed attempt

Drilling the hole in the lid

Finished bolts

Finished bolts, opened, screwdriver bit shown

TODO


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