Best manufacturing operation to make flat cosmetic aluminum parts

Try using a laser. They don't give as smooth a cut as waterjet,but it will be a lot cheaper.

I am no expert, so my advice is worth what you pay for it, but I have seen many manufacturing processes over the past years and it often surprises me at the look of the finished part compared to how the same part looks as an unfinished part.

The bumper you illustrated probably was not done in a one step operation, but saw many different processes to achieve the look that the finished part has. If I were to guess, I would say the the part was made like this.

1. Blanking and/or blanking and cutting of the slots.
2. Drilling and chamfering of the holes.
3. Bending of machined blank to fit mounting brackets.
4. Finishing (buffing, vibratory finishing or abrading)
5. Plating or anodizing.

It is very difficult to take a raw piece of metal (or any material, wood, plastic, etc.) and form it to its finished shape without leaving some type of machining or handling marks on the raw part. A finished appearance part like this almost always needs some type of secondary finishing operation to give the part its pleasing "finished" look.

thank you for your replies. the water jet is pretty cheap. about $1/part.

i'm looking at some tumblers and some easy ways to hold the smaller parts to ease the buffing process. what is abrading? concerning plating/anodizing, how much imperfections come out if plated or anodized? thanks allot.

well, lately i've been finishing the parts with good results but too much labor time. Using 220 grit to get the larger deeper blemishes down, then scotch bright to get a uniform brushed type finish.

To speed things up i just picked up a bench buffer and hope that will give me a better finish in less time. I'm always trying to improve the quality of my parts. If it doesn't take too much time i might put a mirror finish on the parts. That would be nice!