57AZ From United States of America, joined Nov 2004, 2586 posts, RR: 2
Reply 1, posted (7 years 8 months 2 days 15 hours ago) and read 2733 times:
I don't know which specific parts would have been chemical milled, but I'd wager that they did. Chemical milling began to come about in the late 19th and early 20th centuries as an improvement to physical milling, which tends to place certain stresses on the billets. I believe that it has less of a negative impact on the physical strength of the metal than physical rolling or milling-the compression alters the molecular structures of the metal slightly.
"When a man runs on railroads over half of his lifetime he is fit for nothing else-and at times he don't know that."
DALMD88 From United States of America, joined Jul 2000, 2744 posts, RR: 14
Reply 2, posted (7 years 8 months 2 days 12 hours ago) and read 2716 times:
I know Chem mill parts have been used on Boeing skins. There have been numerous crack problems on the 737 classics at the chem mill areas near the wing fairing area. If I recall there were also some Chem mill parts on Douglas aircraft.
Tdscanuck From Canada, joined Jan 2006, 12710 posts, RR: 80
Reply 3, posted (7 years 8 months 3 hours ago) and read 2586 times:
Quoting DALMD88 (Reply 2): I know Chem mill parts have been used on Boeing skins.
I don't know about the early jets, but chem milling is certainly used extensively on the current Boeing production line aircraft. Fuselage skins are the most common area for it but it also shows up in other spots, like 747 floor beams.