Reldys... my last attempt to explain this to YOU.
REF
FAA-H-8083-31-V1 Aviation Maintenance Technician's handbook - Airframe V1
Open V1 and then Go-To
Figure 4-125 Minimum bend radius [for aluminum alloys] (from the Raytheon Aircraft Structural Inspection and Repair Manual)
NOTE that the minimum permitted bend radius [BR] for 2024-O and 2024-T3/-T4 are in totally different columns; and are substantially different Radii!
For example, per this table...
(A) 2024-O, 0.100 thick, can be safely bent to BR 0.22. AFTER forming the part MUST BE heat treated to attain -T4 [-T42] temper (parts are NEVER used in -O [annealed] condition).
(B) 2024-3/-T4, 0.100 thick, can be safely bent to BR 0.44. After bending, NO FURTHER ACTION IS REQUIRED [except to visually inspect for cracks in the BR].
It IS OBVIOUS, or should be obvious, that these processes are completely different and may in fact be a order of magnitude different in cost...
Heat treatment [-O, form, HT to -T42, inspect, apply finish] WILL increase the cost for a simple part 5X to 15X+ and will take days to properly manufacture.
Whereas the no heat part [MF -T3, form, inspect, apply finish] can be made in minutes and be ready for installation shortly thereafter [after application of finish].
This draws a OBVIOUS POINT: The heat treatment option is ONLY specified when severe forming is required [various reasons]. IF The original engineering specified -O material HT-T42 there was a dammed good reason for it... IF it specified -T3 then no severe forming was expected so why bother pouring company resources into non-value-added work?
OK there are special cases where these guidelines can be violated.... but very rare/far-between. There are also a LOT OF DETAILS that are missing in his explanation to KISS.
IF THIS doesn't give You an 'AH-HA' moment, then You need aluminum fabrication training... not counseling/advice we're trying to provide in this thread.
Regards, Wil Taylor
o Trust - But Verify!
o We believe to be true what we prefer to be true. [Unknown]
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation,Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", Homebuiltairplanes.com forum]