Spectral works to the MIL-A-8625F Type III standard for engineering hardcoat.
View the Mil-A- 8625F spec sheet.
On 6061 alloy, the standard thickness of our engineering hardcoat is 50 microns thick. On dimensionally critical parts, we can tightly control the growth of the hardcoat film to +/- 5 microns.
Mohs’ hardness of engineering hardcoat is only exceeded by diamond. From a scale of 1 – 10, where diamond is the hardest mineral at 10, engineering hardcoat is placed at 9.
Rockwell hardness is difficult to quantify as the impact hardness of the anodic film is dependent on the hardness of the base aluminum.
Engineering hardcoat cannot be coloured and is not clear in appearance. The natural anodized colour depends on the thickness of the anodic film as well as the aluminum alloy. For 6061, the colour ranges from medium brown (50 micron coating) to dark grey (76 micron coating). For alloys such as 2024 and 7075, the colour could vary from tan to dark green.
Engineering hardcoat is also referred to as salvage hardcoat because it can be used to increase the dimension of an undersized part. Typically, an expensive machined part can be saved if it is undersized by no more than 30 microns per surface.
**Our large engineering hardcoat tank can anodize parts up ten feet long.