Hi t_rod7018,
The T-6 designation has nothing at all to do with the finish... "T" = Temper, and in the case of "T-6" let's first understand what the letter "T" for Temper really means...
Basic Aluminum Heat Treatment Designations:
F - As Fabricated - No special control has been performed to the heat treatment or strain hardening after the shaping process such as casting, hot working, or cold working.
O - Annealed - This is the lowest strength, highest ductility temper
H - Strain Hardened - (applied to wrought products only) Used for products that have been strengthened by strain hardening, with or without subsequent heat treatment. The designation is followed by two or more numbers as discussed below.
W - Solution Heat Treated - This is seldom encountered because it is an unstable temper that applies only to alloys that spontaneously age at ambient temperature after heat treatment.
T - Solution Heat Treated - Used for products that have been strengthened by heat treatment, with or without subsequent strain hardening. The designation is followed by one or more numbers as discussed below... So basically the letters represent one form or another of heat treatment that was used to manufacture the aluminium alloy for a variety of applications... Now let's look @ the number designations that immediately follow the letter designations...
Heat Treating T Temper Codes
T1 - Cooled from an elevated temperature shaping process and naturally aged to a substantially stable condition.
T2 - Cooled from an elevated temperature shaping process, cold worked, and naturally aged to a substantially stable condition.
T3 - Solution heat treated, cold worked, and naturally aged to a substantially stable condition.
T4 - Solution heat treated, and naturally aged to a substantially stable condition.
T5 - Cooled from an elevated temperature shaping process then artificially aged.
T6 - Solution heat treated then artificially aged.
T7 - Solution heat treated then overaged/stabilized.
T8 - Solution heat treated, cold worked, then artificially aged.
T9 - Solution heat treated, artificially aged, then cold worked.
T10 - Cooled from an elevated temperature shaping process, cold worked, then artificially aged.
*Additional digits may be used after the first T temper digit to indicate subsequent stress relieving by processes such as stretching, compressing, or a combination...
So there you have it... I hope this explanation will help you better understand what "T-6" really means.
Lawrence, We're on the same page buddy and you assumed correctly.
Respectfully,
Henry
P.S. Here's another great site to learn more about aluminum welding and it's various alloys from AlcoTec, and offers Aluminium Welding Training as well as the Knowledge Center and ESAB University which covers many different topics related to Arc Welding in general and is not restricted to aluminium only... In this page are other links to the Knowledge Center and once there, you can also visit Aluminum Welding Questions and Answers:
http://www.alcotec.com/us/en/education/index.cfm So you're Borinquen? Do you know what that means in the Taino language? Answer: Its an indigenous TaĆno name, which means "Land of the Valiant Lord". Yo soy Americano! parents from DR & Cuba... Bendiciones... ENJOY!