TM 1-1500-204-23-6
(5) Temper designation. The temper designation follows the alloy designation and is separated from it by a
dash (refer to table 4-3). The fullhard condition is classified as -H1 8; 3/4-hard as -H16, 1/2-hard as -H14, and 1/4-hard
as -H12.
(6) Coding. Identification of aluminum alloy is assured by marking each piece. Marking is accomplished, at the
mill, as outlined in the following paragraphs (a) and (b).
(a) Sheet, plate, and bar (3/8 inch or larger in width). These pieces are marked by painting required
information listed below along the length of each piece.
•
Manufacturer's name or trademark.
•
Specification number
•
Nominal thickness (sheet and plate only).
NOTE
Aluminum alloy sheet and plate are marked in rows, approximately 5 inches apart.
(b) Rod and tubing (1/2 inch or larger in diameter). These pieces are marked by stamping manufacturer's
name or trademark and specification number along the length.
(7) Marking by painting. Every effort should be made to identify the type of aluminum alloy, when it has not
been marked by the mill, and identification indicated by color marking. The marking should consist of painting color
bands on each tube, bar, rod, sheet or plate, using enamel, MIL-E-7729.
NOTE
Aluminum alloys that require marking, but cannot be identified and marked, should not
be used for repair of aircraft.
(a) Method. There are ten colors used in this identification marking system to represent numbers 1, 2, 3, 4,
5, 6, 7, 8, 9, and 0 (refer to table 4-4). These ten colors are also used to represent letters F, H, O, T, W, A, B, C, D, and
S. A combination of these colors, representing a combination of numbers and letters, are used to mark material to
denote its material designation. For example, aluminum alloy with material designation 2218-T6 is marked green, space,
green, blue, white, space, yellow, and red (see figure 4-1). The commercial designation, AISI (American Iron and Steel
institute), and SAE (Society of Automotive Engineers) numbers are utilized as material designation numbers.
Table 4-3. Temper Designations
-F
As fabricated
-0
Annealed, recrystalized
-H
Strain hardened
-H1
Plus one or more digits. Strain hardened only
-H2
Plus one or more digits. Strain hardened and stabilized
-H3
Plus one or more digits. Strain hardened and stabilized
-W
Solution heat-treated unstable temper
-T
Treated to produce stable other than -F, -O, or -H
-T2
Annealed (cast products only)
-T3
Solution heat-treated and then cold worked
-T4
Solution heat-treated
-T5
Artificially aged only
-T6
Solution heat-treated and then artificially aged
-T7
Solution heat-treated and then stabilized
-T8
Solution heat-treated, cold worked, and then artificially aged
-T9
Solution heat-treated, artificially aged, and then cold worked
-T10
Artificially aged and then cold worked
4-4
