Dating old nails
The wood fibres would often swell if damp and bind round the nail making an extremely strong fixing.
In Tudor times, we have evidence that the nail shape had not changed at all as can be seen by the nails found preserved in a barrel of tar on board the 'Mary Rose' - the Tudor flag ship of Henry VIII built in 1509 and recovered from the mud of the Solent in 1982.
The strip of metal was then turned through 180 to cut the next equal and opposite nail shape off the strip. Because the nail up until then was handmade, the first machines were naturally designed to re-produce the same shape of product - a square tapered nail with a rosehead, but only tapered down two sides of the shank.
The nails are generally used for doors, floors, gates, indeed anywhere a period nail has to be displayed.
The cut nail was produced in large numbers and various other shapes were devised to suit different purposes.
By the start of the 1900's, the first coils of steel round wire were produced and quickly machines were designed to use this new raw material.
Then the nail maker would insert the hot nail into a hole in a nail header or anvil and with four glancing blows of the hammer would form the rosehead (a shallow pyramid shape).
This shape of nail had the benefit of four sharp edges on the shank which cut deep into timber and the tapered shank provided friction down its full length.
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As explained earlier, the first cut nail machines replicated the handmade nail - the square tapered nail with a rosehead.