Jeweling

[SteveWag]

The marks left after “jeweling” or “engine turning” were once a mark of high quality on finely fitted cast iron parts. This is because during the 1800’s and up to WW2, accurate grinders were not commonly available. So say you wanted a very “flat” plate, I mean FLAT. You would take two moderately flat plates, put a VERY thin coat of stain or ink on one plate, lay one on top of the other, flat faces together, and while pressing together, move one about a quarter of an inch. Now, where the high spots on either plate came together there was a transfer or a rubbing off of the stain. These high spots were then “scraped”off. The scraping typically removed no more than 0.0002”. Then the plate was restained, they were again placed together, but one plate was rotated 90 degrees, and the process repeated. Every time this was done the “high” spots roughly doubled in number. The scraping was done in a way that left a half turn mark. As the process continued, with the “high” spots doubling every time and each high spot being removed with a half turn pattern. The tightness of the pattern indicated the “flatness” of the part. This scraping was very prevalent on things like lathes, mills, drill presses and other machine tools. Anyway, the pattern was a mark of quality work. As the need for scraping became a lost technology, the marks were made for decoration. The machine industry named the decorative pattern after the process used to create the pattern, namely, engine turning, that is the pattern is created by a machine – engine – and was turned – tool was rotated. In the case of firearms the process is done for appearance, or decorative reasons hence “jeweling”. Actually, the small grooves hold oil so they do have a positive advantage.

Steve

[CommonHighrise]

Rep added for a good history lesson!

[deth502]

yes, it was a nice story. if only it werent bullshit.


first off, to create surface plates you need 3 plates to scrape and alternate pairs between them. if you only used 2 plates, you would just be making one surface plate to have a mirror image of the irregularities of 2nd plate.

the "frosted" look caused by scraping has nothing to do with engine turning or "jewling".

jeweling is a very simplified version of of an old artform used to decorate expensive watches and jewelry.

the name of the artform that origionated is actually "Guilloche" which, as far as any can tell, originated in france, but even that was a spin off of an old technique used on softer matls like wood and ivory. the patterns were usually very intricate and formed designs, much more in depth than anything youll find on a firearm now a days, with just the basic straight line turning.