- Molds/die products-used as a mold/die release to reduce sticking and wear
- Machinery-rotors, gears, bushings, bearings, etc.
- Electronics-heat sinks, control panels, capstans, data processing equipment
- Aerospace components-actuators, valves, impellers, etc.
- Automotive-mechanical parts, racing pistons
- Marine parts-boat spars, fittings, etc.
- Ordnance-all U.S. service branches require hard-coating
NOTE: Reason for difference in coating quality on die casting is that 218 is 9.4% alloying elements of which the principal is magnesium. Magnesium is not detrimental to HARDTUF and, in fact, there are some high magnesium proprietary sandcasting alloys (such as Almag 35) which anodize very rapidly and well, 360 and 380, however, are 11.60% and 13.80% alloying elements respectively, and the principal elements are silicon and copper. Both, but specifically silicon, are detrimental to a good anodic coating.
Characteristics as applied to:
Most common: 1100 only Bronze-grey in color at .002 inch, alloy is soft and not particularly good for machining. Maximum practical coating thickness .0025 inch.
Most common: 2014, 2017, 2024, 2618 (forgings). Avoid sharp corners on 2011 and 2017; grey-black at .002 inch to blue-grey at .002 inch. Excellent machining coating .002 inch; .0025 inch possible for salvage though not as hard as less heavy coats.
Most common: 3003. Good for die work and machining. Grey-black in color at maximum coating of .002 inch.
Most common: 5005, 5052. 5005 best for die work;
5052 not good for die work, except black. Both have good machining characteristics, Maximum practical coating .002 inch.
5052 has excellent dielectric properties when coated to .002 inch.
6000 & 7000 Series
Most common: 6061 6063 and 7075. 6061 forms excellent hardcoat for grinding, lapping or honing. Excellent dimensional stability. 6063 used for extrusions. Maximum practical coating .0025 inch. 7075 for high strength applications.
Reynolds and Alcoa make high stability tool plate (wrought and cast, respectively). Both can be HARDTUF coated. Maximum practical coating is .0025 inch.
Most common: 319, 355, 356, also 40E, Ternalloy, Tenzalloy and a variety of proprietary alloys. 356-T6 is used most often. Grinds and polishes very well. Porosity can cause apparent pits in coating. Anodize will not fill in pores. Maximum practical coating .004 inch.
Die Cast Alloys
Most common: 218, 360, 380. Only 218 produces hardcoat comparable to that on wrought or sandcast, 218 is difficult to die cast.
Maximum .0015 inch. 360, 380 maximum about 001 inch. Color is black. Not as wear resistant as 218.