The new system uses an identification-marking and code (Table 5-5) and has its own color-code
breakdown. For each number used (1, 2, 3, 4, 5, 6, 7, 8, 9, and 0), there is a designated color (column
1). The numbers are listed in column 2, and the letters (F, H, O, T, W, A, B, C, D, and S) are listed in
column 3. For example, blue is designated as the number 1 and the letter F.
Table 5-5. Identification marking and color code breakdown
A combination of these colors, which represents a combination of numbers and letters, is used to mark
the material to denote its general composition or condition, where applicable. In the example shown in
Figure 5-12, the aluminum tubing's identification markings for the base-metal color codes are green,
black, green, and orange; and for the temper- and strain-handening color codes are yellow and red. By
comparing these colors with the adjacent numbers and letters in columns 2 and 3 of Table 5-5, above,
you can identify this metal as 20-25-T6.