|
Date: |
|
Description: | After the tacks were made they went to be 'blued'. Bluing is the process whereby metal is heated to prevent crystallisation. If the heads of tacks were cold formed in the machine, they would sometimes crystallise, resulting in the head of the tack breaking off when it was knocked into wood. Bluing eliminates this; the tacks were originally annealed in a furnace by heating to a dull red and when they came out they were blue in colour, hence the name. With today's modern materials, crystallisation does not occur so the bluing process is purely cosmetic, although it does help to prevent rust. Consumers expect to buy blued tacks so they continue to be supplied in this way. As it is no longer necessary to anneal the tacks, they are simply tipped into a rotating barrel and heated with a gas flame. | License: | http://creativecommons.org/licenses/by/2.0/uk/ | Publisher: | Wolverhampton Archives | Rights holder: | Wolverhampton Archives | Subjects: | Factories Photograph Photographs Nail making | Temporal: | Jan 2005 | Source: | Black Country History | Identifier: | http://www.blackcountryhistory.org/colle... | Go to resource |
|
|