Originally Posted by
Loose rivets
I recall an FO correcting me when I said that the leading edges of a BAC 1-11 wing were then 'taken to another location and annealed.' He explained the difference between annealing and normalizing.
Wasn't there mention earlier in the thread about the casting of Pickle Forks? I took the answers to mean, originally they were milled from the solid, but later cast with substantial oversize and then milled down to size. I know the metal cad be recovered, but the effects on the finished casting are serious science. I'm given to understand that even the way a hole is drilled is incredibly critical; the speed and sharpness of the tip being stipulated by the boffins.
The first article I read on the pickle forks (sorry, can't find it now) said that originally, the part was cut from billet aluminum, creating a lot of waste. It also had to then be shipped to a subcontractor on California for 'normalization'. The new forks are forged, (not cast), and 'don't need to be normalized', or shipped to California. (I suspect that maybe they still do.)
Aha! From Waterpilot's comment (#10) above: "To increase materials efficiency, the main component of the pickle fork is now produced out of forged, restrike aluminum. Previously the part was produced from block aluminum, which generated a significant amount of scrap because the pickle fork component was cut and shaped from the block. The pickle fork forgings now arrive in the approximate shape of the component so less aluminum is scrapped. In addition, the type of aluminum previously used for the pickle fork required shipping to California for stress relieving and return back to Auburn for continued production. The current aluminum forgings do not require stress treatment."