I have been approached by many customers asking how to get a darker looking finish on stainless steel parts. The truth is, there is simply no right or wrong answer when trying to achieve a specific finish, and it is simply down to trial and error.
The biggest influence towards the appearance of the surface finish is primarily based on the blasting media type.
Generally speaking, glass bead is a spherical particle and has a peening action which will result in a much brighter finish.
On the other hand, Novaculite or any other form of aluminium oxide leaves a topography on the surface which is not reflective, giving a darker looking finish.
In order to achieve a smooth yet dark finish there are two possibilities. Acid pickle the finish after the cleaning process or to simply use a 50/50 mix of glass bead and Alox.
If there is a specific finish you require and you are not sure which media type you should be using… just ask Rick!