Material Precautions                       

	Alloy: When placing anodized aluminum of mixed alloys together a customer can expect a visible color difference.
	Temper: Properly heat treated (aged) material will color uniformly
	Coating thickness: Thicker coatings tend to produce a grayer appearance

Alloy 

	Alloying imparts desired  mechanical properties such as: strength, fluidity, machinability, etc.
	Elements may form compounds in the alloy that end up in the anodic coating during anodizing. Mg2Si, FeAISiR, MnAI6, etc.
	Imparts color to the anodic film, therefore not all aluminum alloys look the same after anodizing.
	Different alloys have different conductivity and therefore will anodize and color at different rates.
	1XXX series - 99% pure (very reflective, clear anodic coating)
	2XXX series - Copper major alloying constituent (will color grey yellow on anodizing)
	6XXX series - Magnesium and silicon major alloying constituent (will color light to dark shades of gray)
	3XX series Castings - Silicon major alloying constituent (will color light to dark shades of grey)

The most common Architectural alloys include: 

• 6063 and 6061 for extrusion stock. Silicon is the primary alloying element
• 5005 and 5052 for sheet stock. Magnesium is the primary element. 3003 and 1100 have also been used.

Temper 

	Designation that applies to all wrought and foundry alloy signifying a condition produced within the alloy either by thermal or mechanical treatments F - as fabricated O - annealed H - strain hardened W - solution heat treated T - thermally treated to product a stable temper
	Heat treatable temper is designated T1 through T10 T1 - cooled from shaping operation and naturally aged T5 - cooled from shaping operation and artificially aged (age oven) T6 - cooled from shaping operation, solution heat treated and artificially aged
	T52 - Over-aged condition developed for an old anodizing process known as Integral color anodizing