A little while ago I put a post on the forum, concerning nails that had been modified into screws.
They were used to secure the handles and totes of late Siegley and early Hahn planes.
Both made in Wilkes-Barre Pennsylvania around the 1900's.

At one point I suggested that the barbe's or cleats formed at the top of the nail just under the head.
Were made to help secure it into the timber after it had been driven.
The general consensus at the time was that the marks were only a result of the wire being clamped in place
during the manufacture process, while the head of the nail was struck.

I know in the harsh light of day its of little consequence as to which is correct.
But like a dog with a bone theres that part of me that just doesn't wont to let go!

These are some of the modified nails used in the Siegley and Hahn planes.

IMG_0750.jpg

The picture below supplied by Peter, shows the same style of nail before being modified.

nails.jpg

So in my defence here's two American patents from around the time.

The first one is for a barbed nail.
It shows the Barbe's lower down on the shaft of the nail, but is a good example of the idea at the time.

372844-1a.jpg 372844-2a.jpg
The second Patent is a little later, is for a machine designed to deliberately form the type of marks
we see on the nails.

424227-1.jpg424227-2.jpg424227-3.jpg

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A patent search will quickly show numerous patents for just this type of thing.
At the time there was many schools of thought around ways to stop a nail from lifting.
The version at the top of the nails used to make the screws was just one of them.

History is fickle at the best of times, and it quite often doesn't take long for the purpose of something
to be forgotten.