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Oxide versus anodizing for furniture grade project

2002

I am in the beginning processes of building a rack for holding my audio gear. I was hoping to pick the brains of people in the know. I would like the main structural supports to be half inch black threaded rod of some type with either glass or wood shelving. There are several companies selling racks constructed exactly this way but mine is to be of a unique shape and I would like the satisfaction of creating one myself. My problems now is deciding which type of metal/finish to use. I would like to keep the cost down but will play give and take with finish versus cost. My first choice (not knowing anything about the costs yet) would be black anodized aluminum threaded rod. Second would be black oxide steel. Third a natural finish such as brass or bronze, and fourth a natural steel hidden behind some cover (split loom tubing?).

My questions are: Would black oxide be a good choice for a furniture grade project? Would it easily scratch off when running nuts up and down the threaded rod or under the minor load of the torqued down nuts? Do these coating change the size of the rod enough to interfere with the fit of the nuts? I would prefer a deep black with some shine. I think that oiled black oxide would supply this but is this achievable with anodizing or is a matte finish all that I can get?

Also having no knowledge of metal or finishing, what information should I supply to the finisher and what questions might I ask? Could anyone offer a rough price ratio between steel/oxide and aluminum/anodized processes? It would seem with my brief research that aluminum rod cost about 75% more than steel so if anodizing is twice as expensive as oxiding then I might be looking a 3 or 4 to one ratio in pricing? Any suggestions from the experts? I would be grateful for input and opinions.

Thanks,

Gregory Sheehan
- Cranford, New Jersey

The problems with black oxide is that it will rust fairly quickly, and it must be kept lightly oiled; on the other hand, black oxide is so thin (millionths of an inch), that changes in thread interferences will not occur.

You would be better off, I think, with your first choice of anodized aluminum, although this will add about 3 ten thousandths of an inch to the interference. Black anodizing can be bright; it usually isn't made so because this leads to very obvious fingerprinting (although this is probably not an issue on something with no flat surfaces like a threaded rod).

Usually there will be a minimum lot charge that will negate any cost differential between anodizing and black oxide.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2002

Hi,

I am looking to do the exact project you are, but am not having luck in finding the threaded aluminum rods. I am also looking to do the black anodized. Could you enlighten me as to where you found them for purchase?

Thanks,

Ken Perr
- Newport Beach, California
2003